You can apply users to certain surveys. If you apply the low level users to only one survey (Country 1, Region 1, Area 1), then they can only see these responses. The region users will receive access to all area surveys in their region, the country users will receive to all surveys of all regions and all areas and so on.
You can add users to surveys. You might be able to do something via groups, but I don't have the time to think aobut this in detail and test it. All in all, it will be quite some work as you will have a lot of surveys (countries*regions*areas).
Help us to help you!
Provide your LS version and where it is installed (own server, uni/employer, SaaS hosting, etc.).
Always provide a LSS file (not LSQ or LSG).
Note: I answer at this forum in my spare time, I'm not a LimeSurvey GmbH employee.
