Indent headers in left navigation panel


Hoping for some help with creating API documentation with the Postman tool.

Using Markdown, I’m going to list out some common use cases for our API. I’d like the individual use cases to show up in the left navigation, but it seems that only the h1 header appears in the navigation panel:

Is there a way to indent or nest headers of the documentation in the navigation panel on the left so that it looks like “Pay an insured or claimant” belongs to the “Use Cases” section?