Hi Chandan,
Add a table with Region, Reporting Period, Fact1, Fact2 and then create a Break on Region. If you run the report for multiple months, it'll show them grouped by Region. Now, if you drill down on one of the Region, you should see the data for that Region only by Month(s) and the Facts obviously.
Check this out:
Web Intelligence 4.0: Create breaks between groups of data
Hope that helps.
Thanks,
Mahboob Mohammed