You can create an event in Registrations, then create a group with the attendees from the event.
For example, you may want to create a group for each age category within a VBS event.
The following steps require permissions in People, Groups, and Registrations. This process can be a collaborative effort with people who have those permissions, or an Administrator in those applications can give those permissions.
1. Create an Event in Registrations
First, create the event in Registrations.
If needed, create attendee types that you want to form the groups.
Create a List
Once you've created your event, create a list in People for the attendees who have registered for the event. Make sure to add the specific Attendee Types or other criteria for the people that you want to add to the group.
You can set a list automation to add them to the group, so as people begin the register for the event, they are added to this list, which then adds them to the group.
Email Group Members
Whether you create a Registrations Event or a People Form, the automations will begin to fill up the group as people submit information.
When enrollment closes or once the group is full, welcome the group members by sending them an email.
You can also set up an automation in People to email people when they are added to the group.