Example: our org has 11 Networks that are geographic (E.g. Europe, Latin America etc). Would it be possible to configure CiviCRM so only staff within our Europe network could see records (contact details, financial details etc) within their network?
There is also a Permissioned Relationship approach that can work well for multilayered organisations using this Fuzion extension
Yes, you can do that. Read up on CiviCRM Access Control to get started.