Is this what you are looking for ? check the attached...
I created a "Fund Type (Adjusted) dimension" based on the parameter.
From this I created a set in order to remove the null and I use it as the filter. If you use this dimension directly on the filter shelf, you would have a null checkbox, which in your case is irrelevant.
Book4 ed mc.twbx 230.2 KB
As far as I know, when you select a filter. It literally filters that data out of the view. So if you have filtered out MT & ETF, that data will not show.
I would try creating a calculated field (or changing the one you have made) to where if the user selects "Private-funds" it automatically "filters" out MT & ETF.
to do something like I mentioned you will have to "Group" them by hand. (EDIT: I believe if you have Tableau 10 then you can use groups in a calculation and skip this step) something like:
then add this to your filter for the parameter
I'm not sure if this is the direction you'd like to take- as it may end up with more problems. I have little experience with how financial data is supposed to work. But hopefully something sparks an idea!
Thank you, @MichelCaissie. I think this is going to work for me. I knew I had to be missing something.
And to @Matthew Risley, thanks for your reply as well.