I am Indian national and traveling from USA to India via HongKong and my USA visa has been expired. Do I need a transit visa to enter or change the flight in Hong Kong?
You won't need a transit Visa if you are transiting via Airside and not getting out of Airport.
You can verify the information here - https://www.traveldoc.aero
By the way, Hong Kong offers free Visa for short period for Indians, but you have to register online before travel.