If you wish to build a group form, it would be the following menu items:
1.04 Group Registration - (form texts, banners, confirmation email)
1.05 Group Login Texts (Group profile)
1.06 Group Login Links (links to edit the group profile, download invoice templates)
3.03 Activity Groups
3.04 Activities (they are also shared between individual form and group forms; there is a setting that can make the activity available only on the group form: Display only on Group form).
If you have any questions please do not hesitate to contact by submitting a request.