In your current document, only the sections named “Part I” and “Chapter I” are formatted with styles that will be included in the table of contents. If you expect more sections to appear there you need to make sure that they are formatted using the same styles as “Part I” or “Chapter I”.
If the other sections already have their own style (but different from Part or Chapter), you can include it in the TOC by clicking in one of these sections, then open Paragraph > Styles > Enumeration/Table of Contents and check the “Title (for table of contents / Navigator)” checkbox. Apply and close the Style window.
After that, you should see your sections in the Navigator. If you do, go back to the TOC, right click there and select “Update Table of Contents”.