I understand how to use the custom calculations in the field settings in
pivot tables to derive a simple annual growth rate, using % Difference From,
(previous), and the year field .

Does anyone know a similar way to generate compound annual growth rates
(CAGRs) in a pivot table for each year in the series from the initial base
year?

I have tried doing a calculated field, but then the column total reflects a
sum of the CAGRs and not the CAGR for the total.