Try right-clicking on the column header and selecting Hide from the pop-up menu, this should do the trick.
That specific column will remain hidden, but its data will be available for calculations (unlike filter).
When years go by, you may want to hide a different column, and if you want that to happen automatically, then you need to create calculated fields along the lines of "First year", "Second Year" etc, that will dynamically update based on the current date or something like that.
My sheet looks something like this:
Cases Dollars Dollars YoY Difference
2011 2012 2011 2012 2011 2012
------- -------- -------- -------- ------- ---------
55 65 500 600 BLANK 100
I don't want that blank column for Dollars YoY Difference - 2011. But I can't see a way to hide that one column alone.
I'm not sure I follow what you're saying...if click on the year 2011 in the header and hide, it hides that year for all my columns. If I click on the actual "Dollars YoY Difference" header, it hides that column completely, both years.
It seems like you need to have a field that is specifically '2011 Dollars' and '2012 Dollars' and then calculate the difference between them. But then I need to redo this every year. It seems odd that Tableau wouldn't allow you to do something this simple.