Continous data replication between two databases(same RDS instance) in AWS RDS

We have multiple databases in a single RDS instance. Forex A, B, C A and B DB contains the plans table. But some of the fields will be missing under the plans table in B DB. What is the smart way to keep these tables in sync(like continuous replication)? I check AWS DMS When I created a source point using the RDS instance for A DB. It gets successfully created. But when I tried to create a target endpoint for the same RDS instance with a different DB. It is throwing this error. SYSTEM ERROR MESSAGE:ReplicationEndpoint "database-1" already in use with endpoint ARN "arn:aws:dms:ap-southeast-1:59351853185:endpoint:VLRTOQM7LBW5M7YUKPOENBTFDUC32N7B5737I" Am I looking into the right tool or is there any other tool available for this scenario? Any insight on how to achieve this will be greatly appreciated. Thanks