SubAdmins create groups

I’m looking to see if anyone has figured out how to add to the subadmin ability in NextCloud 12? I have a client who has their own server, they want to be able to create groups on their own, which is fine by me, but I do not want to give the same admin capabilities (change/install apps/etc) to this user. I have already made them admin over a group or two, but they need the ability to create new groups without being a super admin.