Implement it as on any other community websites. Begin with adding Adobe Launch embed code to every page. Then even the simplistic Analytics deployment will help see page views and bounce rate by page and aggregated.
Help make Adobe Analytics better, vote for the ideas:
Hi @g4cloud not sure if you're still curious about how to solve for this, but my company Stoke provides this integration (Salesforce Communities tracking into AA). If you're having difficulty accomplishing this please feel free to DM me.