When you use the PowerPivot field list you can only add a measure once to the Values area.
In my case I needed to show the sales value both as values but also as the % running of total.
Instead of creating a new measure in the power pivot model – I choose to show the Field list from the Pivot table tab in the ribbon.
From the field list I can add the “Sales Value” field several times and choose to show the value as % Running Total in
Or choose it from the shortcut menu when you right click the field.
You should be aware of when changing the label in the pivottable to “Share of xx” it will rename the field in the pivottable list and the pivottable field list will show you the latest name you have renamed your fact to.
In this case I have added sales value 2 extra times and chosen Rank largest to smallest and renamed the field “Sales Value” to “Rank” by changing the label.
So instead of creating complex DAX expressions – sometimes Excel functionality can do it for you.