You can make a custom calculation that equals
TotalSum = Above Target + ..... + Balance to Target
Then make new calculated fields for each of your measures such as
Above Target / TotalSum
On a different note however, there are many people who would advise you not to use a pie chart. They are widely considered less useful than bar graphs. Alas, I'm not the type to preach to you.
Hope you are enjoying Tableau,
Thank you for helping.
OK, I creted the TotalSum field and I can create the new calculated fields for each measure but that's where I get stuck. I don't know how to use those new calculated fields to construct the pie chart. I thought the max measures in a pie chart was two? I have six.
Thank you again for the help