Hello Margrette,
I think, that we are using a similar scenario:
You could start with a Watch Events module looking for newly created tasks or projects (depending on what your target object type is).
For tasks and projects there are the fields convertedOpTaskID, convertedOpTaskEntryDate and convertedOpTaskName, which only have a value, if they are originating from a converted issue (OPTASK). One of these should be your filter.
Afterwards you could use the Read Related Records module to check on your issue, if there are any douments (Collections). If yes, you can use the Misc Action module on those documents with the action moveToFolder and set the desired folderID of your target object.
The detailed setup depends on several parameters, including, if the converted issue is preserved or not.
Regards
Lars