首先，您需要使用hide_empty至少发表一篇文章来获得所有产品类别。

然后遍历每个类别并针对每个类别运行查询以获取单个产品。

$args = array(
    'orderby'    => 'name','order'      => 'ASC','hide_empty' => true
);
$product_categories = get_terms( 'product_cat',$args );
$count = count($product_categories);
if ( $count > 0 ){
    foreach ( $product_categories as $product_category ) {
        echo '<h4><a href="' . get_term_link( $product_category ) . '">' . $product_category->name . '</a></h4>';
        $args = array(
            'posts_per_page' => 1,'post_status' => 'publish','post_type' => 'product','tax_query' => array(
                'relation' => 'AND',array(
                    'taxonomy' => 'product_cat','field' => 'slug','terms' => $product_category->slug
                )
            ),);
        $products = new WP_Query( $args );
        echo "<ul>";
        while ( $products->have_posts() ) {
            $products->the_post();
            ?>
                <li>
                    <a href="<?php the_permalink(); ?>">
                        <?php the_title(); ?>
                    </a>
                </li>
            <?php
        }
        wp_reset_postdata();
        echo "</ul>";
    }
}