Some suggestions.
Deselect all (currently to deselect all you need to select all first).
Select all files with more than 'n' fragments (ie either enter the 'n' of fragments or right click on a file with 'n' fragments). For example more than 50 fragments
Select all files that are greater than 'n' bytes in size (ie either enter the 'n' of bytes or right click on a file with 'n' bytes). For example more than 1 MByte
Select the top 'n' fragmented files by no of fragments.
Select the top 'n' fragmented files by file size.
