Core

Currently there is a field to enter a domainname to lock fe_users to.

Based on the idea of feature #34342 Claus Due suggested if this field also allowed wildcards and multiple-domainnames (maybe comma-separted).

Another good idea might be to not use necessarily use that input-field to add the dommainname to each and every used again but have a multiselect that allows to add relations to domain-records. This way domainnames would be stored in a central place and only references from users to domains would need to be created.