BuddyPress.org

@anton-naydenoff installing group and/sitewide forums with BuddyPress – https://codex.buddypress.org/user/setting-up-a-new-installation/installing-group-and-sitewide-forums/

As for possible conflicts with BP Group Hierarchy plugin, I haven’t used the plugin so maybe someone else can chime in or you might want to check it out yourself and post your findings here.