[Jeff Sayre]

Are you trying to integrate an existing bbPress install with BP group’s? Or, is this a brand new bbPress install with no data?

If the latter, there is no reason to do a separate install of bbPress. BuddyPress comes with a barebones version of bbPress already. It allows BP Groups to each have their own forums. However, it does not allow for the creation of a sitewide forum.

If you have an existing bbPress forum that you’re trying to associate with BP, then the bbPress tables must be installed into the same database as your WordPress tables. Make sure that you have read this BP Codex article: https://codex.buddypress.org/buddypress-site-administration/using-an-existing-bbpress-installation/

Finally, if you’re trying to have a standalone, global bbPress forum on your site, and not just have BP Group forums, then read this: https://buddypress.org/community/groups/how-to-and-troubleshooting/forum/topic/how-do-i-create-a-non-group-specific-forum