Switch Camera mode from fixed to free

Hi guys,

I need some help for making my blueprint system :

I have have a third person camera attached to a springarm and i want this camera to be free of moving (with left stick pad) from the current location when i push a button, then i can look my character from a different point of vue.
When i repress the button, the camera come back behind the character.

Anyone have an idea for doing this ?
Thank you for helping

The following video by Daerst explains how to do this very well, he goes over a few different ways to get this to work. Hope it helps!