This is a DBA's task.
One answer: CTAS (create table as select ... )
Another answer is: expdp/impdp.
But, it sounds like you are trying to create a dev environment.
You're better off having a full copy (or as close as possible) of production.
But beware of Oracle Licensing...your Dev and Test environments have to be fully licensed also.
You have to "link" the 2nd schema to your workspace in order for that 2nd schema to show up in the drop-down lists.
You do that in the Admin Portal.
Manage Workspace -> Manage Workspace to Schema Assignments.
Oh... and make sure you have given the correct GRANTS to your parsing schema.