Hi and Yes.
You select what camera you are looking through by clicking on the camera name at the top left hand side of the viewport window. This menu is useful for saving locations within the scene so that you can try new locations without losing the old ones.
I’ve uploaded an older screenshot .
Also in the ‘View’ menu switch on the ‘show production frame’ option. This will display the border for the active camera.
The directors camera will not show a production frame because it is not a production camera.