How do I turn categories into a navigational menu?
If you're not familiar with categories, you can learn more about them here. A category is something you can add within the Build > Items step when creating or editing your collection page. Categories can not only create visual separation among groups of items, but they can also be turned into a navigational menu that people visiting your collection page can use to easily filter your items and get to what they want more quickly. This is a great feature if you have 5 or more items on your collection page.
To turn categories into a navigational menu, on the Items step, click on the "Display Options" button at the top of the view. This will allow you to toggle on the option to display your categories as a drop-down menu at the top of your collection page. You can even determine which specific categories should be added to the navigational menu. See below for examples of where to add this feature as well as the resulting menu on your collection page.