Add AD (LDAP) user to group

Nextcloud version (20.0.4):
Operating system and version (eg, Ubuntu 18.04LTS):

I have Nextcloud with two AD Domains in LDAP and it seems to work fine except, how do I add AD users to a Nextcloud Group.

I have a Nextcloud group “Nextcloud admins” from which I would like to add a handful of users from each LDAP AD Domain.

When I go to the group “Nextcloud admins,” I see the list of existing users, but no way to add users? If I go to the users list. there are many users and no good search feature?

Any ideas?