You can do casts only to your parent or child BPs, so this setup wont work. Furthermore i suggest you forget about casting everytime you want to access some actor at runtime, especially on loops, because it lacks perfomance.
If you want to execute some function or event and you need to confirm that this particular actor can make it (for what you are using cast node i guess), you should just use interfaces. With them you dont need to cast everytime and they are more flexible than regular functions and events for some sort of things.
