You can’t do that from the spring arm, unfortunately you have to set the collision channels to the rest of the actors to not block the camera channel instead.
Since we are talking about the spring arm, there is also no option for self-collision… let’s say your pawn is a tank and you want the camera to no go through it for example, you can’t.
Definitely something that Epic needs to work on, there is also a weird camera jittering bug with it that I reported a few weeks ago.