To limit the results to specific IP locations, add the following to the Criteria column for the tsysIPLocations.IPLocation expression, replacing what we've marked in yellow and leaving the single quotes in the syntax:
In ('First location name','Second location name')
Keep in mind that this is standard SQL syntax. We highly recommend familiarizing yourself with SQL, as this will make it a lot easier to build or modify reports.
This forum topic lists some resources you can use.