Hi Ksb288,
If I understand correctly, you would like to display the aggregate value along with percentages on the same pie chart. In this case, I suggest to add an expression in the Label data tab to achieve the goal. Please follow the detailed steps below:
1.Right click pie chart and select “Show Data Label”.
2.Right click data label and select “Series Label Properties”, and add the expression in “Label data” tab, as shown below:
=FormatPercent(sum(Fields!SalesAmount.Value)/sum(Fields!SalesAmount.Value,"DataSet1"))+ "sum:" + cstr(Sum(Fields!SalesAmount.Value))
Through the above steps, we can obtain a similar chart as follows:

Regards,
Heidi Duan