MULTCLOUD will help you transfer files across cloud drives and centralize their management. And it is FREE!
This is a great tool to transfer backups off server to a cloud storage, Multclould has connectors to Various Clouds Supported and FTP. At the same time, you can handle multiple accounts in one provided by the same service provider.
Supposing that you have registered two accounts in Google Drive, it can manage all the files of both accounts simultaneously.