I may be missing something, but do you have a Date field you can place on the filter shelf, and display the filter at the year level?
Imagine 4 columns, the first is company, the second is the year (201,2011,2012), third is the sales category and fourth is the amt
I bring that into tableau and create a time series were you see the trend for each company in a given category.
However, I want to allow the user to limit his view to a range of sales from 2012..in other words, say the various companies had sales from 50K to 750K in 2012 in a given category..I want the user to be able to show only those companies that had 2012 sales between 100K and 250K, and show the respective time series (that is the tricky part)
Its very difficult for me to imagine the problem or answer your original question based on a written description--I'd say your best bet is to upload a sample workbook with your problem demonstrated, so users here can take a look. I'm quite positive it is possible, but how it would be done would depend on a number of factors.
Someone else may chime in with a better response, based on your written description, but I'd imagine most folks are going to ask for a packaged workbook. See: http://community.tableau.com/docs/DOC-5065