Have you looked at protocols? You can define protocols for your views or objects, and the users of that object (the subviews underneath for example) can implement the protocol, set itself as the objects delegate and when actions happen they will notified through the protocols. So for example
An AboveView will declare a protocol that declares methods when a certain gesture was senced by that view so something like -(void)didMakeCircleGesture... as a property the underneathview will have a delegate, so in your method that actually sence the gesture youll have at the end something like
[delegate didMakeCircleGesture];
in turn the delegate is the view underneath or something, and it will conform to the protocol defined by the AboveView, and as part of it it will have to declare the method didMakeCircleGesture, so as a result when one makes a circle gesture in the AboveView the underneath view that conformed to the protocol will be told of the event and it can take appropriate action