The AG's Tools | AG_showOutgoingHiddenInputs v1.0

>> Shows outgoing hidden inputs <<

By default, Nuke shows you the incoming hidden inputs... in other words, you can see where the 'pipe' is coming from, but not where it goes.

With this little tool you can see the outgoing hidden inputs by simply pressing the hotkey. I set it on 'alt+2' but you can change it the way you like.