subdirectory
Specifies a prefix in the S3 bucket that DataSync reads from or writes to (depending on whether the bucket is a source or destination location).
DataSync can't transfer objects with a prefix that begins with a slash (/) or includes //, /./, or /../ patterns. For example:
/photosphotos//2006/Januaryphotos/./2006/Februaryphotos/../2006/March