I developed a worksheet in Tableau 10.5 based on my understanding of your requirement and attached. There are couple of options. Is this what you are looking for? Let me know.
Conditional Labels.twbx 2.4 MB
Thanks so much for your help, it worked on one of the workbooks but I now want to use it on another. When I try to adapt your calculation to other workbook data I get the error "Cannot mix aggregate and non-aggregate arguments with this function". My date dimension is discrete and is called [Reporting Day], and the measure is aggregated and is formatted as percentage.
I wish I could upload the workbook but the data is confidential. Perhaps I can provide you with some information that can help you understand why I am getting this error?