making sub categories under forms categories

Hi!

I am working now in the "forms" module and I wondered if there is a way to make sub categories under the main categories, for helpful organization.

For instance, in FORMS - data items- posts - post categories

Can I make a main category like "Community" (non check-able) and then under that, have the checklist of check-able boxes like "Dating" "Seeking Friends" "Community Service" "Volunteers"

Things like that? It would really help if possible.

Thanks! :-)