Yep, goes to the washer tank. If your plastic line is too short to reach it is snapped in two. Those lines get brittle with age, if the rest of it is still attached to the wiper pump, use a piece of tight fitting vacuum line to splice the ends. if it is missing, you will have to rig up some vacuum line all the way to the pump.

I hate those little plastic lines, every time I work on an older vehicle at work the damn things break. Usually the vacuum line going in to run the HVAC system.