The source and target databases do not need to be separate – in fact, the replication can replicate back to the source database. Provided that the target tables/schemas are different than the source tables/schemas.
To setup such a configuration, specify the same database TNS identifiers during the first step of the setup (case-sensitive).
During the setup wizard the following rename question is asked. By answering yes, a rename for the schema can be given.
Specify rename name for any of the specified schemas (yes/no): [yes]
Rename name for schema AVI (empty means no rename): 
DDL replication is not supported when replicating from one schema to another schema as the objects have a different name.