If you already have a lot of sections in your notebook, you can create a section group to keep your notebook sections more organized and more easily accessible.
In OneNote, a section group lets you combine a selection of multiple sections into their own group (or groups). When you open a particular section group, you’ll see only those section tabs that you’ve chosen to move to or create in that group — making it much easier to navigate through the section tabs of a large notebook.
For example, instead of having twelve section tabs (one for each month of the year) on your row of section tabs that can easily scroll out of view on a smaller Mac screen, you could create four section groups (one for each quarter of the year), and then move the section tabs of the corresponding three months in each quarter to their corresponding section group.
In any notebook, do the following:
On the menu bar, click File > New Section Group.
While its temporary name is highlighted, type a meaningful description for the new section group, and then press Return.
When you click the tab of the section group you’ve created, all of the normal section tabs at the top level of your notebook disappear to make room for the sections you’ll create in (or move to) the current section group. To exit the current section group view and return to the top level of all of your notebook sections, click the curved arrow icon to the left of the section tabs.
To add new sections to the section group you currently have open, click the [+] section tab at the top of the page, and then create any necessary pages within each added section. Alternately, to add existing sections and pages from this or any of your other notebooks, you can move or copy notes. As with normal sections, you can organize the sections in a section group by dragging their tabs to the left or right.
To rename a section group, first exit the current section group by clicking the curved arrow icon to the left of the section tabs. Control-click the tab of the section group you want to rename, and then click Rename. When the current section group label is selected, type the new name for that section group.
If you accidentally create an extra section group, you can delete it. First, exit the current section group by clicking the curved arrow icon to the left of the section tabs. Control-click the tab of the section group you want to delete, and then click Delete. Be careful — when you delete a section group from a notebook, all of the sections that the group contains will also be deleted — including all of the pages contained in each of those individual sections, plus any inserted files and attachments that those pages may contain.