Configure users to only see other users of the same group

Is it possible to configure users so that they can only see other users of the same group? I am using a hosted NC28.02 and could not find any obvious option, maybe there is a less obvious one?

It’s not obvious what you mean by “see” other users.

you can limit sharing to the groups where user is member:

https://docs.nextcloud.com/server/latest/admin_manual/configuration_files/file_sharing_configuration.html#file-sharing-configuration

for address book user and admins can set different options:

https://docs.nextcloud.com/server/latest/admin_manual/groupware/contacts.html#system-address-book