[dba-VB] C# Filtered Combos

I am trying to filter a bound combo when another combo changes selection.  I have to tell you this 
is overwhelming my tiny mind.  My form is bound and I have three combos also bound.  There must be a 
DOZEN objects down in the foot of my form - datasets, binding sources, tableadapters and binding 
navigators.  Too much stuff.  It's like each bound object drags along three different things just to 
make it work.

Am I doing this right?  Which piece would I modify to change the sql that changes the data displayed 
in the filtered combo?
-- 
John W. Colby
www.ColbyConsulting.com