Hey @shallow!
So there isn’t an “Undo Function” or anything. But, you can usually find a way to reverse things.
For example, with your SpawnActor, take that return value and promote it to a variable.
Then, on the next one, use the Destroy Actor node and pass in that variable, which would be the actor you spawned on the first Out of the MultiGate.
If you want it to be random, you can make a function out of it (maybe call it “Undo SpawnActor Out 0”) and have the function use that variable, use a gray “IsValid?” check and on True, destroy actor, then put that function before the MultiGate. You could make reverse functions like this for every possible branch to “reset” any branches before choosing a new one.
Hope that helps and let us know if you need more assistance!