Summary
How to filter by starts-with for 3 RTF columns?
Content
Hi All,
I have a list of results that I need to evenly show across 3 columns to look like this:

I'm not exactly sure how to do this. One idea I have is to just add a filter in each of the 3 columns for Starts-with 'A to E' for Column 1, ''G to P" for Column 2, "R" for Column 3.

I have the 3 columns built but I'm not sure how to filter the content in each of them.

The group row by code is:
<?for-each-group:row;./FIELDVALUE?><?sort:current-group()/FIELDVALUE;'ascending';data-type='text'?>
Any advice?
Thanks,
John