You can implement it in a single shot, you have to change all your expressions in your Dashboard. Create one variable like below
vUserName = OSUser()
Now in your set analysis try like this
I think it is not possible with section access also.
Hope this helps you.
Thanks a lot for your reply jagan . But as I mentioned I can do this by editing in all expressions and dimensions. But anyways Thanks a lot for your answer. Looking forward for your helps.
Loophole in this way is user can still search but yeah I can exclude searches from this field ,Thanks once again.