Im not sure all the details of your model, but I know some of them have optional daylight run lights. If they are programmed from the factory with DRL then the second switch may not do anything unless you have the dealer deprogram it or you work around it.
The other possibility is that the switch you are referring to deals with separate lights - always on parking lights, etc
I know for my 4th gen, theres DRL, if i turn the head light knob further, I get an additional set of lights, and then full turn is the headlights