OK, now I’m scratching my head.
When I create a second group, even if I tag the fields in the second group as “required”, they don’t show up on the register page (the bp-default version). The second group only shows up on the user’s profile page where they can edit the fields. They are tagged as “required” but nothing seems to force the user to fill them out.
I’m confused now as to what you’re seeing and/or trying to do.