Greetings! If you are referring to Select Groups, at your Default Group Policy, Click the + to add a new group. There you will see an option on the Description field “This is a ThinOS Select group parent”, check this box. You can optionally add specific admins below.
Now click Save.
With the new Select Group created you can now create policies under the select group, i.e. Broker 1, then another for Broker 2. Note, add user devices to the group that will be the default group for the user. What the user will see is a login screen with a dropdown for the other brokers defined.
Hope this helps.