I was with the same doubt as you.
The fact is: there is no easy method to o so, like a get_current_camera()
What you could do is what I did, I keep track of the camera:
Add a script to your camera and keep track of what camera is the current by passing the reference of it to a global variable Globals.set("currentCamera", self)
If you want to make this automatic, add the code to the _process
loop function and also, checking if the camera is current first...
It should look something like that:
_process(delta):
if is_current():
Globals.set("currentCamera", self)
so, you could get the pos or all the methods and info from it later by doing: Globals.get("currentCamera").get_pos()
I didn't use this in the process function, I prefered to do the checking and swaping myself, but other than that, it worked flawlessly for me with everything I needed.