Place this formula in the
Group Footer #1 section of your report.
Because the Group Footer #1 section
appears once for every group, @AmountDisplay will execute each time a group
ends. So, the value stored in the Amount variable will be printed each time the
group changes.
Note: This formula
prints the same value that @RunningTotal prints as the running total for the
last record in each group. Because it is printing it in the Group Footer
section, it acts as a group subtotal, not as a running total.
On your report, each row in the
running total column displays the current record value added to the previous
values. The running total starts fresh with each new group, and the final
running total for each group becomes the subtotal for that group.