The level of sections and sub-sections shown in the Table of Contents is a setting you can change.
To get H3 headings to show up in the Table of Contents, go to your book's Theme page here:
...making sure to replace YOUR_BOOK with your book's unique web address.
Next, click the "Custom" button at the top right.
Scroll down and select "Parts, Chapters, Sections and Sub-Sections" under "Table of Contents":
Finally, make sure to save the change, by scrolling to the bottom of the page and clicking the "Update Theme" button:
The next time you create a preview, you should see the H3 headings in your Table of Contents.
OK, that's it!
If you have any feedback or questions about this article, please email the Leanpub team about it at firstname.lastname@example.org!
If you have any questions or thoughts on writing and self-publishing with Leanpub, please join our global community of authors in our Authors Forum here!
Interested in creating your first Leanpub book? Here are some quick tutorials for our most popular writing modes: http://help.leanpub.com/en/articles/3088382-quick-walkthroughs-for-getting-started-on-a-leanpub-book
Are you looking for great deals on Leanpub ebooks, ebook bundles, and courses? Sign up for our Weekly and Monthly newsletter sales here!