If the completed document is exported as a HTML or PDF then the clickable links in the TOC will be preserved.
My example here will be with the public domain book A Princess Of Mars from which the movie John Carter came from.
This book was written by Edgar Rice Burroughs, the creator of Tarzan.
Then I click on Insert and then select Indexes and Tables and then click on second Indexes and Tables
Then I click the white space just left of E button
Then I clicked the Hyperlink button.
Once you click the Hyperlink button, a new button titled LS will appear Left of the E button. This is normal.
Then click your Hyperlink button.
Once you click the Hyperlink button, a new button titled LE will appear right of the E button. This is normal.
Note: if you make any changes to your document that would change the start location of your chapters etc. You will then need to right click on your TOC and select Update Index/Table.
Or you can click on File and select Export as PDF