When you have a Query Subject selected, in the Properties window edit the Security Filters and assign certain groups certain data. Ex. [Database View].[Query Subject].[Item] = ‘HR Group’
This way requires constant maintenance and publishing/deploying if you add any groups to Cognos.
FIRST: you must have security groups that MATCH the data you are filtering (in your case ‘HR Group’, ‘Dept’, etc.) - see the bottom paragraph if you don’t already have this. When you have a Query Subject selected, right-click, Edit Definition, choose the Filters tab, Add a filter, choosing the same query subject, apply a macro that looks up the user’s group to see if they can get the data you want. Ex. [Database View].[Query Subject].[Item] in (#CSVIdentityNameList()#)
So you’d create a Query Calculation that looks something like this:
CASE [Database View].[Query Subject].[Item]
THEN 'HR GROUP’