You can use the toolbar(_:for:) modifier on your sidebar view like this: .toolbar(.hidden, for: .navigationBar). You can find details in the documentation here. Here's the resulting view: struct SomeView: View { var body: some View { NavigationSplitView( columnVisibility: .constant(.all), sidebar: { Text("sidebar") .toolbar(.hidden, for: .navigationBar) }, detail: { Text("detail") } ) .navigationSplitViewStyle(.balanced) } } The first argument sets the visibility, and the second arguments specifies which bar to hide (which in your case is .navigationBar).

I've noticed that Swift Playgrounds on macOS runs App Playgrounds as Mac Catalyst apps, so I suppose this would be the case for Xcode submissions too.