You can create a hyperlinked TOC in Writer that not only lets users click on an item to go to that page, but is still hyperlinked when you export the document to PDF.
1. Apply paragraph styles (Heading1, etc.) to your heading text and set up outline numbering (Tools > Outline Numbering) to specify which paragraph styles go with what level headings.
2. Choose Insert > Indexes and Tables > Indexes and Tables.
3. In the Index/table main tab, in the Evaluate Up To field, specify how many levels you want to see. Usually you want to see 2-3 levels.
4. Click the Entries tab. Follow the directions in the following illustration.
5. Click OK. You'll see the linked TOC.