Hi Akram, thank you for your suggestion. Unfortunately, that doesn't seem to do the trick.
I am currently on Tableau 9.2, and even after unchecking that box, the formula is still visible in both Desktop and Server.
It would seem that the only way to not display the formula is to remove the Tooltip entirely. But this won't work for us since we need the Tooltip.
Any other ideas? =\
When you select the header of the column it always shows the formula.
So do not show header of the column as an alternative use "Text" control as a header of the chart on the dashboard.
Select "Timeliness" column and uncheck "Show header". If you hover over the donut chart you will still get the tooltip without formula even on multiple selection over any chart.