Search users and groups in NAS

My open-e DSS v6 is connected to AD for authentication. This hosts a huge amount of users and groups.
When configuring the users and groups that have share access, I can also search within the users and groupd that have been imported from AD. When I want to add a user and/or group to the Access Control List then there is no option to search, only selected from a scrolling list. Pretty undoable when having thousands of groups and users (20k+ users, 250k+ goups). is there a way to do this more easy?

We know about this issue and we hope to have this worked on in one of our future releases but we dont have a set date as to when it will be released.