Display all sub-category

I made a custom post type and a taxonomy with pods. My custom post type is call books and category_books is my taxonomy. I have novel, biography and comics as category. Both novel and comics have children.

books
  - novel
    - sci-fi
    - fantasy
  - biography
  - comics
    - marvel
    - dc comic

I also have a side menu that display category_books as a navigation menu. When I click on a term it redirect to a page that list every books with that term as category. The problem is that I use $term->name to display my list and novel and comics show nothing since my post are link with their children.

$params = array(
  'limit'     => -1,
  'where'    => 'category_books.name LIKE "%' . $term->name . '%"'
);

Is there a way to look if a term have a child and if it does then list all their post? I want to do something like: if I click on novel it would list all the post link with sci-fi and fantasy and if I click on sci-fi it show normaly (just sci-fi).

https://ww.wp.xz.cn/plugins/pods/