It has been noted in Supervisor 1.7.0.56x that if a duration is entered, it shows the search result - but when using the export to CSV or FTP option, then it gives an error 'No recordings in search result'
Suggestion:
Don't enter a duration as part of the search criteria.
CSV export: You can sort the file by duration and manually remove the duration you do not require.
FTP export: You won't be able to exclude the recordings you don't require.
Try the following: do an export to CSV and get the list of recording reference for recording you require (as explained above). Use it to move the recording files to a required location.