How to revert camera back to previous view after using iron sights in a fps/3rd person game

I’m following online tutorials for making my own fps/3rd person game.
I have three cameras, one for first-person, one for third, and one for the sights down a gun.
I’ve managed to set it up so that I can change the character’s viewport easily, and to zoom in with the sights. V for changing the viewport, and right mouse button for the zoom.

However, when I do zoom in with the sights, no matter which viewport it is in, it always goes back to third person. So if I were in third person, it would go back to that after zooming. If in first person, it will also go back to third person after zooming.

My question is, how would I go about getting it so that it goes back to the previous viewport after zooming?
There’s also a pic of my work so far.
Any help would be fantastic!!

your answer maybe is in this scenario
in part 1 “Camera Boom” reach to zero but in part 2 that set “Camera Boom” 300 so the camera is far like the third person

I will be honest, that section if from the online tutorial and I have no idea why that is there- only that it works for what I want with changing the view of the person playing.
What i’m wanting is so that, for example, I were in my first person view, I zoomed in with the sights (by clicking right mouse button), then on release, it goes back to first person, rather than third which it’s currently doing- if that makes sense?