What your are describing sounds like how categories function.
1. Your main nav bar can have a link to home, and reviews.
2. Home will show all posts from all categories (unless you set it up to skip the reviews category, which is pretty easy to do)
3. The Reviews link will only show posts from that category.
Right now you are linking to a page called Reviews (https://modestbike.com/studio/?page_id=85) in your main navigation. Pages don’t show lists of posts by default but it’s not too hard to get them to do so. Let me know if you want to go that route.
Alternatively, you can link to a category iteslf instead of a page using something like: https://modestbike.com/studio/?cat=8
where 8 is the id of the reviews category.
Hope that helps, let me know if you need more help.