2D to 3D to 2D camera?

I'm making a metroidvania and I had a thought today. Wondering if it's even possible. I will try to explain it as best as i can.

Starting out with a 2D camera. Think what a normal 2D platformer would look like. The character enters a doorway moving left to right, and disappears through the doorway.

The camera starts to move in toward the doorway. The doorway rotates (although it would appear the camera rotates), and the camera enters (1st person POV). As the camera goes inside, the camera reveals the character, and another a 2D platformer.

My crude image may help. From Left to Right. Top to Bottom.

 

You can use multiple cameras.
Or simply move camera to right place.