How to open the resources from a downloaded game to add another viewpoint?

I apologize I might now have worded the question correctly as I'm not entirely sure how to explain what I'm looking for. Simply put, I'm trying to open a game I've downloaded from Steam, such as, TiltBrush, The Lab, or BigScreen Beta, so I can duplicate one of the controllers and set it to a camera. Basically to create another viewpoint that could follow the player or be stabilized depending on the activity/game.

HTC Vive uses this technique to create "mixed reality" and I've been trying to duplicate the second viewpoint. Ex: https://twitter.com/htcvive/status/776927613663137792

In this picture they have a third Vive controller attached to a stabilized camera while live-steaming a mixed reality feed using a "special" game rig I figured was created in Unity, with the SteamVR prefab.