Buffalo Technology TeraStation HS-DTGL/R5 - Manual (Page 42)

Advanced Settings
Group Management
To.Delete a group, put a check next to its name and
click.Delete. To add a group to your TeraStation,
click.Add.
Add a name and a description to the Add New
Group fields. Put checks next to each Member User.
that you want to be part of the group. Click Apply.
when your group is set up the way you want it.