What are these sensors on the Night Stalkers' Chinook MH-47G?
Those sensors are part of the AN/AVR-2A Laser Warning System. Here is a closeup of the system components.

The AN/AVR-2A is a passive laser warning system which receives, processes and displays threat information resulting from aircraft illumination by laser designators, range finders and beam riding missiles. ... The AN/AVR-2A LDS consists of one interface unit comparator and four identical sensor units.; image from thaimilitaryandasianregion.wordpress.com
These sensors are installed on the MH-47G Chinook, as given in americanspecialops.com

Defensive systems
Common Missile Warning System (CMWS)
Suite Of Integrated Radio Frequency Countermeasures (SIRFC)
AN/AVR-2b Laser Warning System
XM216 Dark Flares (invisible to naked eye)