Using the Unity/VNX/VNXe Management tool ,please refer to the link below to download the tool :
Install and launch the tool (Windows client only), right click and connect to the CIFS(SMB) Unity NAS-SERVER-interface (or DNS name) to manage it directly.
note - do not attempt to connect this tool to the SP management port.
Through the NAS server Audit Policy ,you should enable (Audit Object Access) for both Failure and Success Policies, once (Audit Object Access) is successful, actions is enabled and this will generate events also when files or directories are deleted.
To be able to see successful file or directory deletions events, the NAS Server Auditing Policy must include events of type "Success".