Assuming you are using CategoryFilters, they are intended to filter rows of data, not columns of data, so to make the second one work right, you have to hack around this limitation. I built a demo script that you can modify to make work for you:
Unless I am reading the api incorrectly I haven't been able to figure out a way to easily filter 2 columns.
Sample data:
var data = google.visualization.arrayToDataTable([
['College', 'Resident Per Year', 'Resident Per Semester', 'Non-Resident Per Year', 'Non-Resident Per Semester'],
['Undecided',6090,3045,18868,9434],
['Business and Economics',6972,3486,20114,10057]
]);
What I would like to do is build a dashboard with a couple of drop downs, first a selection filter for "college" then a filter that contains 'Resident, Non-Resident' that would then filter out column 1,2 for selection of non-resident and 3,4 for resident.
I have the first drop down in the dashboard working correctly, that was the easy part using existing examples, but I am struggling to do the 2nd drop down. Am I missing something? Any suggestions?