Need help on a disconnected hose that may be a part of the fuel pressure.

What is your question?

There is a rubber hose that we can't figure out what it connects to. The hose has a small valve that connects two smaller hose, each one running to the front and back of the vehicle. We believe the hose's function involves fuel tank pressure but aren't 100% certain. Any specific advice as to where it connects to would be much appreciated.