Actually, we can clone a PDB from any PDB over the network, as long as they are connected and compatible.
Step 1. Create a database link to the source CDB.
SQL> create database link link_to_test1 connect to system identified by oracle using 'finanpdb';
Database link created.
Step 2: Clone the target PDB from the remote database via a database link.
SQL> create pluggable database finance_pdb from finanpdb@link_to_test1 file_name_convert=('/u01/app/oracle/oradata/orcl/FINANPDB','/u01/app/oracle/oradata/orcl/FINANCE_PDB');
Pluggable database created.
Parallel Creation
If you want to clone a big database, say 10 TB from the source, you can add some degrees of parallelism on it.
SQL> create pluggable database finance_pdb from finanpdb@link_to_test1 file_name_convert=('/u01/app/oracle/oradata/orcl/FINANPDB','/u01/app/oracle/oradata/orcl/FINANCE_PDB') parallel 8;
Pluggable database created.
Step 3: Open the target PDB to READ WRITE.
SQL> alter pluggable database finance_pdb open;
Pluggable database altered.
SQL> show pdbs;