Oracle APPS: restricting users from viewing concurrent requests

How  to restrict users from viewing concurrent requests submitted by other users?

We can use personalization 

(DECODE(IMPLICIT_CODE, 'N', STATUS_CODE,'E', 'E', 'W', 'G') = STATUS_CODE OR DECODE(IMPLICIT_CODE, 'W', 'E') = STATUS_CODE) and (nvl(request_type, 'X') != 'S' ) and (trunc(request_date) >= trunc(sysdate-:JOBS_QF.REQUEST_DAYS) ) and REQUESTOR = (Select FND_PROFILE.VALUE('USERNAME') FROM DUAL)