Until a recent update, SharePoint team sites always had a left side vertical navigation menu. Communication sites always had a top horizontal navigation menu that could be a cascading or mega menu style. Recently, Microsoft rolled out the ability to change a team site’s navigation from vertical (side) to horizontal (top).
Note: This change only applies to team site types. Communication sites are still top horizontal only.
Below are the steps to swap your team site’s navigation orientation. You must be a site owner to perform these steps.
How to change SharePoint team site navigation from left side to top
Navigate to the team site for which you’d like to switch the navigation orientation.
Click the settings wheel in the upper-right corner.
Select Change the look.
Choose Horizontal and then choose either Mega menu or Cascading for menu style.