When creating a registration form for your group is it important to keep these tips in mind as you are getting set up.
Subgroups MUST contain all fields in a parent group- though they may contain more.
Editing a the name of a field or editing the response in a field will change all linked in your community
Ex. Changing ‘Company’ to ‘Company Name’ in a registration form in one group will duplicate these edits across all your groups in that network since the fields are linked together.

Another thing to note is that Subgroups MUST contain all the fields that are in the parent group. However, Subgroups can have additional fields to those in the parent group.