Upon installing the extension and then changing the settings so that 'Collapse this set on initial display' and 'Collapse this set in Advanced Search' are marked with yes, the follow warning of "Custom group 'Areas' already exists in Database' appears. How do I fix this error? We're using Civi 5.0.0
This sounds like a civicrm bug. I have tried locally and have the same error.
I found a work around: you can give the custom group a different title (the title Areas is also used for another group which is reserved).
I have created a bug report: https://lab.civicrm.org/dev/core/issues/141