There was an answer on different options in theme control. But in order to add or update the navigation bar on the top of the community website, you need to go to Admin Panel that requires admin access.
2. Click on Theme from the left toolbar:
3. Go to Navbar:
Here is the format you need to insert the links (here, we are adding the keys for Feature, Services, Pricing, and App Store). Type down the name of the key and the put the link for that key inside |.....| start. Please do not forget to enable and save the changes.
Features | https://tribe.so/features12 | start
Services | https://tribe.so/services10 | start
Pricing | https://tribe.so/pricing9 | start
App Store | https://tribe.so/app-store9 | start