Is there any way to list the child categories only? I just want to filter the Parent Categories
The following code is to display the subcategory instead of parent . I am not sure this is the one as you are trying too.
<ul> <?php $catsy = get_the_category(); $myCat = $catsy->cat_ID; wp_list_categories('orderby=id&child_of='.$myCat); ?> </ul>