Select the maximum subgroup size from the list. If some of the actual data in the file uses a smaller subgroup size, the unused data columns will simply be ignored when the template imports the data.
If the maximum subgroup size is greater than 1, you should also specify whether all of the data values for one subgroup are found on one row of the text file or on multiple rows of the text file.
Sample data layout where all data values in a subgroup are found on one row
Sample data layout where all data values in a subgroup are spread across multiple rows