set DIR to single local user and root

Hi there,

Originally i thought this would be a simple task to change via the GUI however after upgrading from 8.2.2 to 9.3 I dont know if something has changed but we cannot save changes to folder owners/groups in the GUI anymore for File System Explorer  (even when logging in as root) is this an intended design change or a glitch?

We are setting up some NFS exports and essentially want to lock down these to a single local user account within our main access zone, (the system needing to use NFS exports to dump data does not support AD)

I am getting confused with the way OneFS lists ACLs via CLI and essentially want to modify a few DIR to be granted access to 

1) a local user account (local to the main access zone we use), used for mapping NFS that has full access to the DIR in question and nothing else on the cluster

2) 1 AD security group (for helpdesk access essentially)

3) root of course

I have created the local user in the access zone i want to use, however cannot find a clear description of the correct syntax to pull the correct user in from our access zone.