Some pages contain a lot of content but not all of it is important enough to dedicate a separate page to. In this case the in-page navigation is the perfect solution.
The in-page navigation can be used in combination with the 'hero header' and 'basic header'. Navigation items are positioned below the page title and description.
Perfect for content types like business units
Business units contain lots of specific information (location, contact details, ...) that could fit on one page, but this would lead to a very long page where a user would need to browse through all of it to find the needed piece of information. For these cases the sub-navigation allows to divide the business unit page into multiple subsections allowing the visitor to quickly find what they are looking for.
This principle can be applied to other content types.