List sub-categories and their discussions on a parent category?

mirri_cat

How do I list sub-categories and their discussions on a parent category.
I think this should be the expected behaviour but it seems not?

When visiting a category "Ideas" I would like to see what is being said in "Ideas" => "Suggest new Videos" and "Ideas" => "Suggest new topics". Or at the very least see that these sub-categories exist

Thank you.

Goke

Here's a solution: http://vanillaforums.org/discussion/15001/proposed-cascading-categories-first-draft-code-feadback-requested