List Sub-Categories of a Parent Category

Question

I need to be able to list categories that are the sub-category of a specific category that is a sub-category of a primary category.

So something like this:

Print Categories where ParentCategory = 'Parent' And ParentCategoriesParent = 'Main Parent'

So I guess it's a depth of 2.

Kind of a complicated category i'm going for but it will help my users navigate the site much easier.

Answer 1

something like this : http://codex.wordpress.org/Function_Reference/in_category#Testing_if_a_post_is_in_a_descendant_category ??