Custom Wheel Grouping

[Greg Stavenow]

I have a custom mobiscroll instance that has 4 custom wheels.  The trick now is that wheels 1 & 2 should be selectable independently while wheel 3 is the master group for wheel 4.  The selectable values in wheel 4 change depending on what is selected in wheel 3.

To get started, I was looking at Levi's fantastic example here:

http://jsfiddle.net/kovlex/3bScd/9/

Using Levi's example as a start, could somebody show me how to accomplish this?