I am not an ps expert, but there is way to get to know the same.
Following simple CLI from clustershell, will return the list of volumes thta have snapshot created in less than 2 hours.
::> volume snapshot show -create-time >2h
Basically, if 'no-ouput' that means all the volumes here are candidate, if you do get 'some-output' that means except those rest all are the candidate.
Hopefully, some ps expert could provide you with ps commands you need.
I know this is not efficient but that's all I can think of now.