Hello,
There's no such concept in AppDynamics and to my opinion, no need for that. The controller is highly scalable, the protocol can be HTTPS from agents to Controller and the Controller can be deployed in multi-tenant mode.
What are you trying to achieve?
If you want to manage multiple customers in different locations, maybe you should have a look at multi-tenancy:
https://docs.appdynamics.com/display/PRO42/Controller+Tenant+Mode+and+Accounts
Hope it helps
JB