widget_title有3个参数可以用来检查合适的类别。根据这些参数，你可以通过返回一个替代字符串来更改标题。请记住，这也会影响到任何其他小部件。使用以下参数作为基础：

function my_widget_title( $title, $instance, $id_base ) {
    if ( !is_single() ) {
        return $title;
    }

    $post_title = get_the_title();
    switch ( $id_base ) {
        case 'pages': return sprintf( '%s "%s"', $title, $post_title );
        case 'links': return sprintf( 'Links for "%s" post.', $post_title );
        // other widgets ...
        default: return $title;
    }
}
add_filter( 'widget_title', 'my_widget_title', 10, 3 );

2022年，你来啦！

//Customize Woocommerce Category Widget to show title of current category
function dynamic_product_category_widget($title, $widget_instance, $widget_id) {

    if ( $widget_id !== 'woocommerce_product_categories' )
        return $title;

    if ( is_product_category() ) {
        $cat_title = '<p class="widget-title footer-widget">'.single_cat_title()."</p>";
        return $cat_title;
    } elseif ( is_product() ) {
        $cat = get_the_terms( $product->ID, 'product_cat' );

        foreach ($cat as $categoria) {
            if($categoria->parent == 0){
                $topCategory = $categoria;
            }
        }
        return '<p class="widget-title footer-widget">'.$topCategory->name.'</p>';
    }
    
    return $title;
}
add_filter ( 'widget_title' , 'dynamic_product_category_widget', 10, 3);