You can view information about a job or thread's call stack by using either iSeries™ Navigator or the character-based interface.
Select option 11: Display call stack, if active.
If you wish to see a call stack for a thread, after issuing the WRKJOB or the DSPJOB command, select option 20: Work with threads, if active. Then, select option 10: Display call stack option for the selected thread.