Nếu muốn lọc theo thuộc tính không lọc theo chuyên mục nữa thì chúng ta làm như sau (ok)

https://tpcn.nhungspa.com.vn/product-category/accessories/

Khi chưa bỏ

Khi đã bỏ

// 			Remove 
			$query['where'] = "
			WHERE {$wpdb->posts}.post_type IN ( 'product' )
			AND {$wpdb->posts}.post_status = 'publish'"
			. $tax_query_sql['where'] . $meta_query_sql['where'] .
			'AND terms.term_id IN (' . implode( ',', array_map( 'absint', $term_ids ) ) . ')';

    if ( ! empty( $attribute_taxonomies ) ) {
        foreach ( $attribute_taxonomies as $tax ) {
            if ( taxonomy_exists( wc_attribute_taxonomy_name( $tax->attribute_name ) ) ) {
                $attribute_array[ $tax->attribute_name ] = $tax->attribute_name;
            }
        }
        $std_attribute = current( $attribute_array );
    }

    $this->settings = array(
        'title'        => array(
            'type'  => 'text',
            'std'   => __( 'Filter by', 'woocommerce' ),
            'label' => __( 'Title', 'woocommerce' ),
        ),
        'attribute'    => array(
            'type'    => 'select',
            'std'     => $std_attribute,
            'label'   => __( 'Attribute', 'woocommerce' ),
            'options' => $attribute_array,
        ),
        'display_type' => array(
            'type'    => 'select',
            'std'     => 'list',
            'label'   => __( 'Display type', 'woocommerce' ),
            'options' => array(
                'list'     => __( 'List', 'woocommerce' ),
                'dropdown' => __( 'Dropdown', 'woocommerce' ),
            ),
        ),
        'query_type'   => array(
            'type'    => 'select',
            'std'     => 'and',
            'label'   => __( 'Query type', 'woocommerce' ),
            'options' => array(
                'and' => __( 'AND', 'woocommerce' ),
                'or'  => __( 'OR', 'woocommerce' ),
            ),
        ),
    );
}
protected function get_instance_taxonomy( $instance ) {
    if ( isset( $instance['attribute'] ) ) {
        return wc_attribute_taxonomy_name( $instance['attribute'] );
    }

    $attribute_taxonomies = wc_get_attribute_taxonomies();
    if ( ! empty( $attribute_taxonomies ) ) {
        foreach ( $attribute_taxonomies as $tax ) {
            if ( taxonomy_exists( wc_attribute_taxonomy_name( $tax->attribute_name ) ) ) {
                return wc_attribute_taxonomy_name( $tax->attribute_name );
            }
        }
    }

    return '';
}
protected function get_instance_query_type( $instance ) {
    return isset( $instance['query_type'] ) ? $instance['query_type'] : 'and';
}
protected function get_instance_display_type( $instance ) {
    return isset( $instance['display_type'] ) ? $instance['display_type'] : 'list';
}
public function widget( $args, $instance ) {
    if ( ! is_shop() && ! is_product_taxonomy() ) {
        return;
    }
    $_chosen_attributes = WC_Query::get_layered_nav_chosen_attributes();
    $taxonomy           = $this->get_instance_taxonomy( $instance );
    $query_type         = $this->get_instance_query_type( $instance );
    $display_type       = $this->get_instance_display_type( $instance );
    if ( ! taxonomy_exists( $taxonomy ) ) {
        return;
    }

    $terms = get_terms( $taxonomy, array( 'hide_empty' => '1' ) );

    if ( 0 === count( $terms ) ) {
        return;
    }

    ob_start();

    $this->widget_start( $args, $instance );

    if ( 'dropdown' === $display_type ) {
        wp_enqueue_script( 'selectWoo' );
        wp_enqueue_style( 'select2' );
        $found = $this->layered_nav_dropdown( $terms, $taxonomy, $query_type );
    } else {
        $found = $this->layered_nav_list( $terms, $taxonomy, $query_type );
    }

    $this->widget_end( $args );

    // Force found when option is selected - do not force found on taxonomy attributes.
    if ( ! is_tax() && is_array( $_chosen_attributes ) && array_key_exists( $taxonomy, $_chosen_attributes ) ) {
        $found = true;
    }

    if ( ! $found ) {
        ob_end_clean();
    } else {
        echo ob_get_clean(); // @codingStandardsIgnoreLine
    }
}

/**
 * Return the currently viewed taxonomy name.
 *
 * @return string
 */
protected function get_current_taxonomy() {
    return is_tax() ? get_queried_object()->taxonomy : '';
}

/**
 * Return the currently viewed term ID.
 *
 * @return int
 */
protected function get_current_term_id() {
    return absint( is_tax() ? get_queried_object()->term_id : 0 );
}

/**
 * Return the currently viewed term slug.
 *
 * @return int
 */
protected function get_current_term_slug() {
    return absint( is_tax() ? get_queried_object()->slug : 0 );
}

/**
 * Show dropdown layered nav.
 *
 * @param  array  $terms Terms.
 * @param  string $taxonomy Taxonomy.
 * @param  string $query_type Query Type.
 * @return bool Will nav display?
 */
protected function layered_nav_dropdown( $terms, $taxonomy, $query_type ) {
    global $wp;
    $found = false;

    if ( $taxonomy !== $this->get_current_taxonomy() ) {
        $term_counts          = $this->get_filtered_term_product_counts( wp_list_pluck( $terms, 'term_id' ), $taxonomy, $query_type );
        $_chosen_attributes   = WC_Query::get_layered_nav_chosen_attributes();
        $taxonomy_filter_name = wc_attribute_taxonomy_slug( $taxonomy );
        $taxonomy_label       = wc_attribute_label( $taxonomy );

        /* translators: %s: taxonomy name */
        $any_label      = apply_filters( 'woocommerce_layered_nav_any_label', sprintf( __( 'Any %s', 'woocommerce' ), $taxonomy_label ), $taxonomy_label, $taxonomy );
        $multiple       = 'or' === $query_type;
        $current_values = isset( $_chosen_attributes[ $taxonomy ]['terms'] ) ? $_chosen_attributes[ $taxonomy ]['terms'] : array();

        if ( '' === get_option( 'permalink_structure' ) ) {
            $form_action = remove_query_arg( array( 'page', 'paged' ), add_query_arg( $wp->query_string, '', home_url( $wp->request ) ) );
        } else {
            $form_action = preg_replace( '%\/page/[0-9]+%', '', home_url( trailingslashit( $wp->request ) ) );
        }

        echo '<form method="get" action="' . esc_url( $form_action ) . '" class="woocommerce-widget-layered-nav-dropdown">';
        echo '<select class="woocommerce-widget-layered-nav-dropdown dropdown_layered_nav_' . esc_attr( $taxonomy_filter_name ) . '"' . ( $multiple ? 'multiple="multiple"' : '' ) . '>';
        echo '<option value="">' . esc_html( $any_label ) . '</option>';

        foreach ( $terms as $term ) {
            // If on a term page, skip that term in widget list.
            if ( $term->term_id === $this->get_current_term_id() ) {
                continue;
            }
            // Get count based on current view.
            $option_is_set = in_array( $term->slug, $current_values, true );
            $count         = isset( $term_counts[ $term->term_id ] ) ? $term_counts[ $term->term_id ] : 0;

            // Only show options with count > 0.
            if ( 0 < $count ) {
                $found = true;
            } elseif ( 0 === $count && ! $option_is_set ) {
                continue;
            }

            echo '<option value="' . esc_attr( urldecode( $term->slug ) ) . '" ' . selected( $option_is_set, true, false ) . '>' . esc_html( $term->name ) . '</option>';
        }

        echo '</select>';

        if ( $multiple ) {
            echo '<button class="woocommerce-widget-layered-nav-dropdown__submit" type="submit" value="' . esc_attr__( 'Apply', 'woocommerce' ) . '">' . esc_html__( 'Apply', 'woocommerce' ) . '</button>';
        }

        if ( 'or' === $query_type ) {
            echo '<input type="hidden" name="query_type_' . esc_attr( $taxonomy_filter_name ) . '" value="or" />';
        }

        echo '<input type="hidden" name="filter_' . esc_attr( $taxonomy_filter_name ) . '" value="' . esc_attr( implode( ',', $current_values ) ) . '" />';
        echo wc_query_string_form_fields( null, array( 'filter_' . $taxonomy_filter_name, 'query_type_' . $taxonomy_filter_name ), '', true ); // @codingStandardsIgnoreLine
        echo '</form>';

        wc_enqueue_js(
            "
            // Update value on change.
            jQuery( '.dropdown_layered_nav_" . esc_js( $taxonomy_filter_name ) . "' ).change( function() {
                var slug = jQuery( this ).val();
                jQuery( ':input[name=\"filter_" . esc_js( $taxonomy_filter_name ) . "\"]' ).val( slug );

                // Submit form on change if standard dropdown.
                if ( ! jQuery( this ).attr( 'multiple' ) ) {
                    jQuery( this ).closest( 'form' ).submit();
                }
            });

            // Use Select2 enhancement if possible
            if ( jQuery().selectWoo ) {
                var wc_layered_nav_select = function() {
                    jQuery( '.dropdown_layered_nav_" . esc_js( $taxonomy_filter_name ) . "' ).selectWoo( {
                        placeholder: decodeURIComponent('" . rawurlencode( (string) wp_specialchars_decode( $any_label ) ) . "'),
                        minimumResultsForSearch: 5,
                        width: '100%',
                        allowClear: " . ( $multiple ? 'false' : 'true' ) . ",
                        language: {
                            noResults: function() {
                                return '" . esc_js( _x( 'No matches found', 'enhanced select', 'woocommerce' ) ) . "';
                            }
                        }
                    } );
                };
                wc_layered_nav_select();
            }
        "
        );
    }

    return $found;
}

/**
 * Count products within certain terms, taking the main WP query into consideration.
 *
 * This query allows counts to be generated based on the viewed products, not all products.
 *
 * @param  array  $term_ids Term IDs.
 * @param  string $taxonomy Taxonomy.
 * @param  string $query_type Query Type.
 * @return array
 */
protected function get_filtered_term_product_counts( $term_ids, $taxonomy, $query_type ) {
    global $wpdb;

    $tax_query  = WC_Query::get_main_tax_query();
    $meta_query = WC_Query::get_main_meta_query();
    if ( 'or' === $query_type ) {
        foreach ( $tax_query as $key => $query ) {
            if ( is_array( $query ) && $taxonomy === $query['taxonomy'] ) {
                unset( $tax_query[ $key ] );
            }
        }
    }

    $meta_query     = new WP_Meta_Query( $meta_query );
    $tax_query      = new WP_Tax_Query( $tax_query );
    $meta_query_sql = $meta_query->get_sql( 'post', $wpdb->posts, 'ID' );
    $tax_query_sql  = $tax_query->get_sql( $wpdb->posts, 'ID' );
    // Generate query.
    $query           = array();
    $query['select'] = "SELECT COUNT( DISTINCT {$wpdb->posts}.ID ) as term_count, terms.term_id as term_count_id";
    $query['from']   = "FROM {$wpdb->posts}";
    $query['join']   = "
        INNER JOIN {$wpdb->term_relationships} AS term_relationships ON {$wpdb->posts}.ID = term_relationships.object_id
        INNER JOIN {$wpdb->term_taxonomy} AS term_taxonomy USING( term_taxonomy_id )
        INNER JOIN {$wpdb->terms} AS terms USING( term_id )
        " . $tax_query_sql['join'] . $meta_query_sql['join'];

    $query['where'] = "
        WHERE {$wpdb->posts}.post_type IN ( 'product' )
        AND {$wpdb->posts}.post_status = 'publish'"
        . $tax_query_sql['where'] . $meta_query_sql['where'] .
        'AND terms.term_id IN (' . implode( ',', array_map( 'absint', $term_ids ) ) . ')';

    $search = WC_Query::get_main_search_query_sql();
    if ( $search ) {
        $query['where'] .= ' AND ' . $search;
    }

    $query['group_by'] = 'GROUP BY terms.term_id';
    $query             = apply_filters( 'woocommerce_get_filtered_term_product_counts_query', $query );
    $query             = implode( ' ', $query );

    // We have a query - let's see if cached results of this query already exist.
    $query_hash = md5( $query );

    // Maybe store a transient of the count values.
    $cache = apply_filters( 'woocommerce_layered_nav_count_maybe_cache', true );
    if ( true === $cache ) {
        $cached_counts = (array) get_transient( 'wc_layered_nav_counts_' . sanitize_title( $taxonomy ) );
    } else {
        $cached_counts = array();
    }

    if ( ! isset( $cached_counts[ $query_hash ] ) ) {
        $results                      = $wpdb->get_results( $query, ARRAY_A ); // @codingStandardsIgnoreLine
        $counts                       = array_map( 'absint', wp_list_pluck( $results, 'term_count', 'term_count_id' ) );
        $cached_counts[ $query_hash ] = $counts;
        if ( true === $cache ) {
            set_transient( 'wc_layered_nav_counts_' . sanitize_title( $taxonomy ), $cached_counts, DAY_IN_SECONDS );
        }
    }

    return array_map( 'absint', (array) $cached_counts[ $query_hash ] );
}

/**
 * Show list based layered nav.
 *
 * @param  array  $terms Terms.
 * @param  string $taxonomy Taxonomy.
 * @param  string $query_type Query Type.
 * @return bool   Will nav display?
 */
protected function layered_nav_list( $terms, $taxonomy, $query_type ) {
    // List display.
    echo '<ul class="woocommerce-widget-layered-nav-list">';

    $term_counts        = $this->get_filtered_term_product_counts( wp_list_pluck( $terms, 'term_id' ), $taxonomy, $query_type );
    $_chosen_attributes = WC_Query::get_layered_nav_chosen_attributes();
    $found              = false;
    $base_link          = $this->get_current_page_url();

    foreach ( $terms as $term ) {
        $current_values = isset( $_chosen_attributes[ $taxonomy ]['terms'] ) ? $_chosen_attributes[ $taxonomy ]['terms'] : array();
        $option_is_set  = in_array( $term->slug, $current_values, true );
        $count          = isset( $term_counts[ $term->term_id ] ) ? $term_counts[ $term->term_id ] : 0;
        // Skip the term for the current archive.
        if ( $this->get_current_term_id() === $term->term_id ) {
            continue;
        }

        // Only show options with count > 0.
        if ( 0 < $count ) {
            $found = true;
        } elseif ( 0 === $count && ! $option_is_set ) {
            continue;
        }

        $filter_name    = 'filter_' . wc_attribute_taxonomy_slug( $taxonomy );
        $current_filter = isset( $_GET[ $filter_name ] ) ? explode( ',', wc_clean( wp_unslash( $_GET[ $filter_name ] ) ) ) : array(); // WPCS: input var ok, CSRF ok.
        $current_filter = array_map( 'sanitize_title', $current_filter );

        if ( ! in_array( $term->slug, $current_filter, true ) ) {
            $current_filter[] = $term->slug;
        }

        $link = remove_query_arg( $filter_name, $base_link );

        // Add current filters to URL.
        foreach ( $current_filter as $key => $value ) {
            // Exclude query arg for current term archive term.
            if ( $value === $this->get_current_term_slug() ) {
                unset( $current_filter[ $key ] );
            }

            // Exclude self so filter can be unset on click.
            if ( $option_is_set && $value === $term->slug ) {
                unset( $current_filter[ $key ] );
            }
        }

        if ( ! empty( $current_filter ) ) {
            asort( $current_filter );
            $link = add_query_arg( $filter_name, implode( ',', $current_filter ), $link );

            // Add Query type Arg to URL.
            if ( 'or' === $query_type && ! ( 1 === count( $current_filter ) && $option_is_set ) ) {
                $link = add_query_arg( 'query_type_' . wc_attribute_taxonomy_slug( $taxonomy ), 'or', $link );
            }
            $link = str_replace( '%2C', ',', $link );
        }
        if ( $count > 0 || $option_is_set ) {
            $link      = apply_filters( 'woocommerce_layered_nav_link', $link, $term, $taxonomy );
            $term_html = '<a rel="nofollow" href="' . esc_url( $link ) . '">' . esc_html( $term->name ) . '</a>';
        } else {
            $link      = false;
            $term_html = '<span>' . esc_html( $term->name ) . '</span>';
        }

        $term_html .= ' ' . apply_filters( 'woocommerce_layered_nav_count', '', $count, $term );
        // WP_Term::__set_state(array(
        //    'term_id' => 227,
        //    'name' => 'Dưới 200.000đ',
        //    'slug' => 'duoi-200-000d',
        //    'term_group' => 0,
        //    'term_taxonomy_id' => 227,
        //    'taxonomy' => 'pa_khoang-gia',
        //    'description' => '',
        //    'parent' => 0,
        //    'count' => 2,
        //    'filter' => 'raw',
        // ))
        echo '<li class="woocommerce-widget-layered-nav-list__item wc-layered-nav-term ' . ( $option_is_set ? 'woocommerce-widget-layered-nav-list__item--chosen chosen' : '' ) . '">';
        echo apply_filters( 'woocommerce_layered_nav_term_html', $term_html, $term, $link, $count );
        echo '</li>';
    }

    echo '</ul>';

    return $found;
}

Chú ý:

Bỏ thuộc tính này đi thì nó sẽ lọc cả trên tag :)
if ( ! is_shop() && ! is_product_taxonomy() ) {
return;
}

Trước

Sau