They are your low point drains, used to drain the water out of the fresh water system. I've never seen one with multiple positions though. Mine are on/off and I marked them with a Sharpie which way was open and which was closed. I put quite a bit of pink stuff on the ground prior to doing this!! ;o)
Can you trace the pipes?? I was thinking maybe the three way might be the hot water and one side is supply, one is sink, and the other drain?? The other might be cold side, supply, sink, drain, and toilet supply???
A little trial and error is in order......I would try the valves in the differnent positions and mark the handle which way is open to the outside.
Also, Pictures would help identify what you have.
2004 Dodge Ram 2500 Club Cab 4x4 CTD
2007 Sunline Solaris T-276-SR: Misty Blue/Cherry
2001 Dodge Ram 1500 Reg Cab 4x4 OFF-ROAD