Tomas Slancik

while you could implement turning on/off of others using callback scripts if you really want to stick to toggles
but I'd certainly recommend using Button Strip instead

here is a simple example
the dependency link is snown in this case when one node's parameter references another therefore it's dependent on it

in Network Editor's View menu under Dependency Links you can choose Show for Selected or Show For All nodes

that will show you any dependencies between nodes those wires you pointed out
also you will see small arrows for input/output references outside of current path