Hi Kirk,
The original question was related to variables and how the filter panel should be able to change variables if you wish.
If you have a cost centre variable set at the second level node lets say, then the filter panel would not be able to use any cost centres above this level. We had a requirement that a user will have a default, but still be able to select any node of the hierarchy.
What was attempted was to use the filter panel to change the cost centre variable, thus allowing the user to have a default and still select the entire hierarchy. What we found was that due to the unique nature of the filter panel, there was no event method to actually set the variable using this component.
So eventually we resorted to using the dashboard variable panel, however as you may agree this causes a performance hit. 
Cheers,
Phil