You can use the SOURCECATALOG parameter to specify a default catalog for any subsequent TABLE, MAP, (or Oracle SEQUENCE) specifications in the parameter file.

The following example shows the use of SOURCECATALOG to specify the default Oracle PDB named pdbeast for region and jobs objects, and the default PDB named pdbwest for appraisal objects. The objects in pdbeast are specified with a fully qualified three-part name, which does not require a default catalog to be specified.

TABLE pdbeast.hr.emp*; 
SOURCECATALOG pdbeast 
TABLE region.country*; 
TABLE jobs.desg*; 
SOURCECATALOG pdbwest 
TABLE appraisal.sal*;