Microsoft is currently rolling out a SharePoint app bar that features global navigation on all modern SharePoint sites (for targeted release tenants).
The first tab in app bar is a Global navigation. Global navigation is the only app bar tab that can be customized. Read all you need to know about global navigation at: Enable and Customize Global navigation
Topics covered:
Prerequisite for enabling global navigation
How to enable the global navigation?
How to customize the global navigation?
Different options to choose navigation source
How to edit the global navigation?
