When exporting a PDF, you can choose to include bookmarks that help the reader jump quickly to important parts of it without having to scroll or search. For example, the start of every chapter of a book, major articles in a magazine, or important text or figures in a report.
There are two methods for creating PDF bookmarks:
The two methods can be used together in the same document.
PDF bookmarks are a special kind of anchor and so they are primarily managed on the Anchors panel.
Any anchor can be given this special treatment, by turning on Export as PDF Bookmark when adding a new anchor or selecting the bookmark icon to its right side on the panel.
When creating PDF bookmarks from a table of contents, one will be created for every item in the table. Use the Anchors panel's bookmark icons to exclude the auto-created PDF bookmarks for any levels you do not want in your PDF. For example, if you want PDF bookmarks only for table of contents items created from Heading 1 and Heading 2 text styles.
Affinity's PDF (digital - small size), PDF (digital - high quality), PDF (for export) and PDF (flatten) presets are configured to include bookmarks by default.