Hi Don
Apologies for the delay in replying to you. I was able to achieve what I was wanting by doing the following:
In the main data source, move the Currency_Section node to be a child of the ExpenseItems node. This allows the data to have a currency section per expense item, rather than a single currency section covering all expense items
Create a new ‘regular' table with 3 rows and copy the header and footer from Expenses repeating table into the first and third row in the new table
Merge cells on the middle row of the new table and insert a repeating section
Copy the middle/data row from the Expenses repeating table into a new table in the newly created repeating section
Move the Currency repeating section within the repeating section holding the expense items repeating section
Updating a binding in the copy controls where necessary and remove the original Expenses repeating table