Create a bullet journal index in OneNote
When you're using the Bullet Journal approach in OneNote, one of the things you'll want to build as you go is a table of contents for your notes. I don't recommend relying on the page and section listing as your table of contents because they don't facilitate referencing your content if it is in other notebooks. Rather I recommend creating a page in your main notebook as the index for your Bullet Journal and then using links to create the connections.
Creating links in OneNote
The easiest way to create links in OneNote 2013 or OneNote 2016 is to use Ctrl-K. This will pop up a window of your open notebooks, sections, and pages and allow you to create the link by just clicking on the destination. If you havecontent you want to link to outside of OneNote, you can enter a URL directly in the same dialog box.
Moving things around
One of the struggles of Bullet Journaling is if you're using a notebook that allows you to move pages around (such as a Discbound Journal) keeping the index relevant and accurate becomes almost impossible. That's not the case here. By creating an index page with links, it doesn't matter where you move your destination pages to because OneNote will update the links accordingly.
You can create index lists at the notebook and section level quickly and easily, but I've got a twist I use all the time. If I need an index page around a specific topic such as a project, I just create a link page with all the relevant links I need and save that to my notebook. From then on when I need related content on the topic, I just have one page to go to rather than trying to track my information down across all my notebooks.
Pro Tip #2
If you're using the Desktop client for OneNote, you can use square brackets [[ ]] to automatically create new pages in your notebook section. Give this a try and check out how it works:
What you should wind up with is three new pages created under the current page with links to all three on the page you're editing. It's a quick and easy way to generate new pages AND even works with the default template you configure for a section (Pro tip for another day.)