As of now, this routing method will only send the department ID as querystring, like so:
GET /test?departmentId=departmentID HTTP/1.1
Host: jkweqkjhweq.requestcatcher.com
Connection: close
Accept: application/json
Accept-Encoding: gzip,deflate
Connection: close
User-Agent: RocketChat Server
X-Rocketchat-Secret-Token: token_secret
One way of accomplishing what you want is to integrate a bot with Rocket.Chat (Like Botpress or Rasa) that will have more information about the room and visitor and can implement more complex routing logic.