DB_FILE_NAME_CONVERT

db_file_name_convert=('/u02/oradata/proddb01/datafile','/u02/oradata/testdb01',
                      '/u02/oradata/proddb01/tempfile',/u02/oradata/testdb01')

log_file_name_convert=('proddb01','testdb01')

When using an spfile:

alter system set db_file_name_convert='/u02/oradata/proddb01/datafile','/u02/oradata/testdb01',
                                      '/u02/oradata/proddb01/tempfile',/u02/oradata/testdb01' scope=spfile;

alter system set log_file_name_convert='proddb01','testdb01' scope=spfile;