Below are directions for the System Administrator on how to configure and set a default navigation bar for all users. Users may further personalize their navigation bar to add or move components, but users cannot remove or rename the items that the System Administrator adds.
From the home page, click the Setup gear icon
In the Quick Find box, type in "App Manager" and select the item
You'll be brought to the Lightning Experience App Manager page where you can customize your apps. Select the REthink CRE app which says Lightning (Managed) under App Type. Click the drop down arrow next to the app and select Edit.
You'll be brought to the Lightning App Builder.
Select Navigation Items. Choose your object(s) of choice to add or remove from the navigation bar by selecting the left or right arrows. Arrange your objects to your liking by selecting the up or down arrows. Click Save once completed.
Please reach out to Product Support (firstname.lastname@example.org) if you have any questions about modifying the navigation bar for your users.