BuddyPress.org

Yes I made a plugin that does that its been tested up to WP 3.5.1 and BP 1.7 beta 1. Its pretty simple so far, as its still in development. All you need to do is read the readme.txt for instructions about sitewide forums if that is what your using then activate it. Here is the link:
https://github.com/bphelp/private_community_for_bp