How the Navigation Menu Works | Salesforce App Admin Guide

The first item in the Selected list becomes your users’ Salesforce app landing page.
You can’t set different menu configurations for different types of users.
When organizing the menu items, put the items that users will use most at the top. The Smart Search Items element can expand into a set of eight or more menu items and it might end up pushing other elements below the scroll point if you put it near the top of the menu. Anything you put below the Smart Search Items element appears in the Apps section of the navigation menu.
Before you can include Visualforce pages, Lightning pages, or Lightning components in the Salesforce app navigation menu, create tabs for them. From Setup, enter Tabs in the Quick Find box, then select Tabs.
Anything represented by a tab in Salesforce—such as standard and custom objects, Visualforce pages, the Chatter feed, People, or Groups—is visible for a user in the Salesforce app menu, based on the user��s profile settings. For example, if a user is assigned to a profile that has the Groups tab set to Tab Hidden, the user won’t see the Groups menu item in the Salesforce app, even though an administrator has included it in the menu.

Some objects are excluded from the Recent section in the navigation menu, even if you accessed them recently.

People, groups, notes, dashboards, reports, tasks, and events, if these items were added directly to the navigation menu
List views, which are shown only on object home pages, not in the navigation menu
Objects that aren’t available in the Salesforce app, including any objects that don’t have a tab in the full Salesforce site

About the Dashboards, Reports, Notes, Tasks, Events, Groups, and People Menu Items

If you opt to add the Dashboards, Reports, Notes, Tasks, Events, Groups, or People items to the Selected list for the navigation menu, these items appear in the order you specify, just like Today and other individual menu items.

If you don’t add these items to the navigation menu, however, they’re automatically included in the Smart Search Items set of objects and show up in the Recent section of the navigation menu.

Pin an Object into the Recent Section

Users can customize the objects that appear in the Recent section of the navigation menu. If they search for an object in the full site, they can hover their mouse over the object name and click pin search results icon to pin it to the top of the search results. The order of pinned objects in the full site determines the order of the objects that stick to the top of the Recent section of the navigation menu. However, pinning objects in this way causes the unpinned objects remaining in the Recent section to drop into the More element.