Row Level Security Lots of Items

[pricter]

We have requirement that it is the follow:
We have a fact table with 20000 products and numerous of rows.
The user A should see only the 5000 specific products , the user B other 6000 products and user C all products.
Could you advise which is the best way to implement security in FM ?

[bus_pass_man]

Data security filters.

http://www.ibm.com/developerworks/data/library/cognos/page58.html

http://www.ibm.com/support/knowledgecenter/SSEP7J_10.2.2/com.ibm.swg.ba.cognos.cbi.doc/welcome.html?cp=SSEP7J_10.2.2%2F5

http://cognosknowhow.blogspot.com/2012/08/how-to-implement-row-level-security-in.html