Set data in `prepareForSegue` with navigation controller

In prepareForSegue access the target navigation controller, and then its top:

let destinationNavigationController = segue.destination as! UINavigationController
let targetController = destinationNavigationController.topViewController

From the target controller you can access its view and pass data.

In old – now obsolete – versions of Swift and UIKit the code was slightly different:

let destinationNavigationController = segue.destinationViewController as UINavigationController
let targetController = destinationNavigationController.topViewController