UFUNCTION only usable internally by BP "Self"

Is there a way to define a UFUNCTION that is only accessible internally by a derived-BP instance?

I don’t just mean it should be BlueprintProtected, I mean it can only be called internally on “self” – I won’t be able to call the function on a reference to a different instance of the same class – I won’t even see it in the list of possible nodes.

I hope I’m explaining it right. An example of what I want would be the “SwitchHasAuthority” node – but I want to define it in C++ not in a BP.