[_ck_]

You can make a view to do that quite easily.

In fact there is already such a view in “My Views” plugin.

Ignore the completely proprietary query system (BB_Query) that the bbpress api uses, it’s incomplete, brain damaging and 100% non-portable to any other system. Just use real mysql queries instead (that goes for WP_Query as well, I have no idea what they were thinking).