What is this long Bar/Rod on the Boeing MH-47G?
This is the In flight refueling probe, which can be used for refueling while the helicopter is airborne:


(image source: pinterest.com)

It is almost 9 meters long to make sure the rotors do not hit the refueling drogue. You can see it in action in the following picture:


(image source: chinook-helicopter.com)