这会给你你想要的结果。

<?php 

$list_categories = get_categories( $args );
echo "<div class=\'container\'>";
echo "<div class=\'productsubmenu\'>";
echo "<ul>";

foreach ($list_categories as $cat)
{           

if($cat->category_parent == 0)
{
$category_id = $cat->term_id;

echo \'<li class="parent \'.$my.\' "><a href="\'.get_term_link( $cat ) . \'">\'.$cat->name.\'</a>\';


$args2 = array(
\'taxonomy\' => $taxonomy,
\'child_of\' => 0,
\'parent\' => $category_id,
\'orderby\' => $orderby,
\'show_count\' => $show_count,
\'pad_counts\' => $pad_counts,
\'hierarchical\' => $hierarchical,
\'title_li\' => $title,
\'hide_empty\' => $empty

);
$args = array(
\'hierarchical\' => 1,
\'show_option_none\' => \'\',
\'hide_empty\' => 1,
\'parent\' => $parent_cat_ID,
\'taxonomy\' => \'product_cat\'
);
$subcats = get_categories($args2);
echo \'<ul class="wooc_sclist">\';

foreach ($subcats as $sc) { 
    $link = get_term_link( $sc->slug, $sc->taxonomy );
    echo \'<li class="" ><a href="\'. $link .\'">\'.$sc->name.\'</a></li>\';
}


}
echo \'</ul>\';
echo "</li>";
}

?>