There is no easy way to get this from NBU.
The Backup Admins in your company should've documented this during planning and configuration stage.
There should be a protection plan for each client or group of clients, around which SLPs are created.
To 'reverse-engineer', you can run nbsu on the master server.
This will create a list of text files with all NBU config.
The policy list will contain client names for each policy plus SLP used for the policy.
The SLP config will tell you replication details and retention.