We can use below query to find the OPP log for a request ID and its path.

SELECT fcpa.concurrent_request_id request_id, fcp.node_name node_name, fcp.logfile_name logfile_path
  FROM fnd_conc_pp_actions fcpa, fnd_concurrent_processes fcp
 WHERE fcpa.processor_id = fcp.concurrent_process_id
   AND fcpa.action_type = 6
   AND fcpa.concurrent_request_id = &REQUEST_ID;