You can probably do this a few ways, the easyist that I can think of would be to use "Linked Reports" in Report Manager and then in your SQL code to distinguish not the user folder, but the user accessing the report.
The Linked Reports will allow you to post the same report in multiple places without having to maintain multiple reports.
If you track the user running the report in the sql stored procedure, you get more flexibility because the system has that system value being tracked. I don't think the system tracks the folder the report is being run under.
Hope that helps,