Thanks for the answer, but it doesn’t make sense, if there is a relationship in the tables like “Assigned to”, why doesn’t the groups relationship appear?
The field Assigned to is for a particular user. You also need to play around with the Security Groups in order to see the results you want.
When a user creates a record (in any module), the system will assign the security group from that user to the record. But is you haven’t created and assigned any security group to the user, your records won’t have any security group either.
I’ll recommend you to take a close look on how all that works by reading the documentation here:
Hope it helps you to get a better ides on how it works.