groupjive Seeing the groups of a category during registration

Hello,
In short, I'd like members, when registering, to register to groups existing or create a group if it doesn't exist.

When they receive an invitation by mail, they go to the registration page by the link (with CB invites).
As the link gives access to a group, included in a category, I'd like the user to see all the groups created in this category and be able to :
- select the groups he wants to be part of ;
- create a group if it doesn't exist.

I tried differents ways with auto action, conditional and query field, but couldn't manage this.
Do you see a solution or do I have to use php requests ?

Thanks for your help,

Create a new Auto Join field within CB > Field Management if you'd like them to be able to select GJ groups to join during registration. As for creating a group during registration you'd need to utilize the CB GroupJive action in CB Auto Actions to do that.

Thank you, I'll start working with this.