Amazon S3 is an earlier cloud service. Many people create several account for more storage. If you want to copy data from one S3 bucket to another bucket, you can try its share function. But if you wan to move data from one S3 bucket to another cloud drive, things are different.
Traditional way is downloading to the local disk then re-uploading. Here, you can try MultCloud to transfer data from one S3 bucket to another directly. Either another S3 bucket or another cloud drive is OK. MultCloud saves your time. It is a great multiple cloud manager. How to copy data from one S3 bucket to another please visit: https://www.multcloud.com/tutorials/transfer-files-between-amazon-s3-accounts.html