Repeating Table - Sub Totals

1. Drag and drop the repeating group on the InfoPath Form

2. Create a text field which will hold the unique Column A values, Choice A, in the main data source
3. Add a Drop Down List for the field Choice A

4. Set the value the just created drop down list to hold unique values of Column A

5. Create a numeric field which will hold total of Column N for the chosen Column A, in the main data source, as Total N

6. Now set the value of the field Total N

7. This is it. Now we can test.