查询父级分类的子分类

<ul class="bigarea">
                <?php
               $terms = get_terms([
                   'taxonomy' => 'shop_area',
                   'hide_empty' => false,
                   'parent'=>0,
               ]);
   foreach( $terms as $term){?>
                    <li>
                        <figure>
                            <?php the_term_thumbnail($term ->term_id, 'post-thumbnail');?>
                            <figcaption>
                                <?php echo $term->name; ?>
                            </figcaption>
                        </figure>
                        <ul class="cityname">
                            <?php    
                             $taxonomy_name = 'shop_area';$termchildren = get_term_children( $term->term_id, $taxonomy_name );
                             foreach ( $termchildren as $child ) {
                                 $term = get_term_by( 'id', $child, $taxonomy_name );
                                 echo  '<li><a class="each-item" href="#'.$term->term_id.'">' . $term->name . '</a></li>';?>

                            <?php }?>
                        </ul>
                    </li>
                    <?php };?>
            </ul>