Your user account or group membership must have the "Collections: View Collections" permission on both parent and child Collections to view the list of Collections unless your user account has the Make this user a Super Admin setting selected. See the Collections permissions or ask your Administrator for assistance.
Furthermore, your user account or group membership must have the Viewrecord permission from a Collection's configuration to view that Collection's records. See Configure a Collection or ask the manager of that Collection for assistance.
View a record in a parent Collection. The View Record tab displays showing the parent Collection record.
Click on the Relationships tab. The Relationships tab displays showing child Collection record(s). The record(s) from the child Collection is retrieved using the common data key between the two Collections. The data in the parent Collection's key is matched with that in the child Collection's key and the respective record(s) from the child Collection is retrieved.