I think I worked out a solution to this problem. The first step is to add a hidden integer field to your repeat which calculates a sequential number for each record in your repeat.
once(count(${gfs_rpt_time})+1) |
This is the formula for the calculation but replace ${gfs_rpt_time} with any field in your repeat. Now you will have a value of 1, 2, 3 etc for each record in your repeat.
Then, in your report template, add the following where statement to the first part of your repeat section. The structural_repeat_no field should be whatever you called your new integer field.
${#structural_repeat | where:"structural_repeat_no='1'"}
The only other issue is that if you are inserting the repeat values into a single table in Word, the repeats will populate in rows instead of in columns. To overcome this, add each repeat section into a separate vertical table with one column. Add the next table to the right with one column and start the repeat with a where clause that specifies "structural_repeat_no='2'.