I'm not sure exactly what you're looking for. The first thing I noticed is that your data would be quite a bit easier to work with if it was shaped a little differently.
In the source, instead of a lot of columns that divide a measure (in your case, by date) like this:
BRAVO Category Subgroup Aug-12 Dec-12 Jul-12 1-Jun Nov-12 Oct-12 Sep-12 J&J Reportable 1A 0 1 0 0 4 2 0
...Tableau will be easier to work with if the data looks like this:
BRAVO Category Subgroup Date Value J&J Reportable 1A 8/1/2012 0 J&J Reportable 1A 12/1/2012 1 J&J Reportable 1A 7/1/2012 0 J&J Reportable 1A 6/1/2012 0 J&J Reportable 1A 11/1/2012 4
You can find a data reshaping tool here: http://kb.tableausoftware.com/articles/knowledgebase/addin-reshaping-data-excel that will help you reformat the data.
I've attached a sample of the reshaped data and a packaged workbook with it. You can see how much easier it is to work with.
Hopefully that will give us a common frame of reference to work through your specific problem, once you've had a chance to look at the new structure.
I was trying something similar because we have a few reports where users want to compare stuff, so I though I'd give this one a try. I couldn't really follow your version of the data, but tried it with the reshaped dataset that Joshua added.
I coloured the calculation fields so it is easy to see what the calculation is.
Is this helpful?