I’m currently using NavigationView to layout my App for iPhone and iPad depending on the horizontalSizeClass. Since the functions I’m using for NavigationView and NavigationLink are deprecated I wonder if one can achieve something similar with the latest APIs.
Here is the simplified version.

ContentView

struct ContentView: View {

    @Environment(.horizontalSizeClass) private var horizontalSizeClass

    var body: some View {
        if horizontalSizeClass == .compact {
            iPhoneEntry()
        } else {
            iPadEntry()
        }
    }
}

AppItems

indirect enum AppItem: Hashable, Identifiable {
    var id: Int {
        hashValue
    }

    case foobar, profile, welcome, articles, books, websites
    case nested(item: AppItem, nested: [AppItem])

    @ViewBuilder
    var destination: some View {
        switch self {
        case .foobar:
            FoobarOverview()
        case .profile:
            Profile()
        case .welcome:
            Welcome()
        case .articles:
            Overview(navTitle: "Articles")
        case .books:
            Overview(navTitle: "Books")
        case .websites:
            Overview(navTitle: "Websites")
        case .nested:
            EmptyView()
        }
    }

    var name: String {
        switch self {
        case .foobar:
            return "Foobar"
        case .profile:
            return "Profile"
        case .welcome:
            return "Welcome"
        case .articles:
            return "Articles"
        case .books:
            return "Books"
        case .websites:
            return "Websites"
        case .nested(let item, _):
            return item.name
        }
    }

    static var ipad: [AppItem] = [.welcome, .profile, .nested(item: .foobar, nested: overviews)]

    static var iphone: [AppItem] = [.welcome, .profile, .foobar]

    static var overviews: [AppItem] = [.articles, .books, .websites]
}

iPhone Layout

struct iPhoneEntry: View {

    @State var selectedItem: AppItem? = .welcome

    @ViewBuilder
    var body: some View {
        TabView(selection: $selectedItem) {
            ForEach(AppItem.iphone) { item in
                switch item {
                case .foobar:
                    NavigationView {
                        FoobarOverview()
                    }
                    .tag("Overview")
                    .tabItem { Label("Overview", systemImage: "circle") }
                case .profile:
                    Profile()
                        .tag("Profile")
                        .tabItem { Label("Profile", systemImage: "triangle") }
                case .welcome:
                    Welcome()
                        .tag("Welcome")
                        .tabItem { Label("Welcome", systemImage: "square") }
                default:
                    EmptyView()
                }
            }

        }
    }
}

iPad-Layout

struct iPadEntry: View {

    @State var selectedItem: AppItem? = .welcome

    var body: some View {
        NavigationView {
            List {
                ForEach(AppItem.ipad) { item in
                    if case .nested(let item, let subItems) = item {
                        Section {
                            ForEach(subItems, content: ListItem)
                        } header: {
                            Text(item.name)
                        }
                    } else {
                        ListItem(item)
                    }
                }
            }
            .listStyle(.sidebar)
            .modifier(ColumnModifier(appItem: selectedItem))
        }
        .navigationViewStyle(.columns)
    }

    func ListItem(_ appItem: AppItem) -> some View {
        NavigationLink(tag: appItem, selection: $selectedItem) {
            appItem.destination
        } label: {
            Text(appItem.name)
        }
    }

    private struct ColumnModifier: ViewModifier {
        let appItem: AppItem?

        func body(content: Content) -> some View {
            if appItem == .welcome || appItem == .profile {
                Group {
                    content

                    Text("Select something")
                }
            } else {
                Group {
                    content

                    appItem?.destination

                    Text("Select something")
                }
            }
        }
    }
}

Dummy Views

struct Profile: View {

    var body: some View {
        Text("Profile")
    }
}

struct Welcome: View {

    var body: some View {
        Text("Welcome")
    }
}

struct FoobarOverview: View {

    var body: some View {
        List {
            ForEach(AppItem.overviews) { item in
                NavigationLink(item.name, destination: item.destination)
            }
        }
    }
}

struct Overview: View {

    var navTitle: String

    var body: some View {
        List {
            ForEach(0 ... 10, id: .self) { num in
                NavigationLink("(navTitle) number: (num)") {
                    Detail(title: "(navTitle) number: (num)")
                }
            }
        }
    }
}

struct Detail: View {

    var title: String

    var body: some View {
        Text("foobar")
    }
}