Access policy branch for Subdomain?

Does anyone know if there is a way to create an access policy branch that will function similar to Landing URI but will look for a subdomain instead of a URI?

I need a way to identify if the request is coming from one subdomain or another so I can apply different requirements to each.

example: If someone goes to app1.test.com they will be sent down one path of the access policy. However if someone goes to app2.test.com the access policy will send them down another branch of the same policy.

Any ideas would be appreciated it.

Thanks!