Could you be more clear what you want to do?
If you want to simply sort by file type (ie RAW, JPEG, TIFF) it is there - just select "sort by {type}".
If you want to sort files by the condition if a RAW+JPEG pair exists, you can easily create a custom sort with the variable {rawplusjpeg}. It will put all photos that are not part of RAW+JPEG pair at the end (or beginning, if you reverse the sort in the custom sort settings).