I assume that you are working in Office UI Fabric React components and you wanted to create a horizontal menu component in your react solution. Unfortunately, the normal Nav component in the Office UI Fabric doesn’t give you this option. And somehow you reached here by searching for a solution to implement the horizontal menu. You are in the right place then.
https://sibeeshpassion.com/creating-a-custom-horizontal-nav-component-using-react-office-ui-fabric/
