1 of 1 people found this helpful
The problem here is that you have to artificially create a new record in your data for the "no preference" option. A fixed LOD can get you the correct value, but doesn't create that artificial record. My personal preference would be to use a data prep tool such as Tableau Prep to create this new record in the data. Is Prep an option for you? If not, there are some more hacky solutions we can provide.
thank you for quick answer.
I think that the only way is to modify the original dataset, as you said. I have access to Tableau Prep and I will follow your guide on a similar topic (How to add a row in Tableau Prep?).
In my case, they are less than 20 rows, so I added manually the "no preference" records.
Thank for your help - I looked at your tableau public profile, really interesting and source of inspiration.