Adding to the previous reply,
I just tried with a restricted user i.e 'Z' in my case who is a 'APAC' user. And called the service from this user and i can see only the 'APAC' related data as shown below:
http://saphan:8000/SECURITY/XS_Z/salary.xsodata/XS_Z?$format=json
The output is attached,
And by the time i write this, i got an email notification that you already tried and it worked
Regards,
Krishna Tangudu