Scroll converts each page into a section, and then each heading will be converted into sub-section. This sub-section will be put into a parent-section, depending on the size of its heading (h1. to h6.) and the other headings on that page.
Example:

• a h1. heading will result in a sub-section of the top-level section.
• if there is no h1. heading, a h2. heading will result in a sub-section of the top-level section.
• if there is no h1. heading and no h2., a h3. heading will result in a sub-section of the top-level section.
• if there are both h1. and h2. headings, the h2. heading will result in a sub-section of the preceding h1. section.
• and so on...

Additionally, there is only one single heading on a page Scroll merges the section from the page and the section of the single heading. This is useful for wiki spaces, where users have created their own page heading (rather than just using the page title as provided by Confluence).