How to relate Operating System PID and Oracle Concurrent Request ID?

Connect as apps user

SQL> column process heading "FNDLIBR PID"
SELECT a.request_id, d.sid, d.serial# ,d.osuser,d.process , c.SPID
FROM apps.fnd_concurrent_requests a,
apps.fnd_concurrent_processes b,
v$process c,
v$session d
WHERE a.controlling_manager = b.concurrent_process_id
AND c.pid = b.oracle_process_id
AND b.session_id=d.audsid
AND a.request_id = &Request_ID
AND a.phase_code = 'R';

You need your concurrent request ID as an input.
c.SPID= is the operating system process id
d.sid= is the Oracle process id