How do I access a specific child component of an actor blueprint?

Wouldn’t you get the instance of the actor you want the component for, then get the component from that?

For instance, if you have a Controller, you would do something like (and the specific call names might not be 100% but):

GetController->GetControlledPawn->Mesh->etc? or
GetContoller->GetControlledPawn->CharacterMovement->MovementComponent->etc.

or something along those lines…