Example of a Form, embedded in a NavigationView, which has a Section and Picker. When Selecting an item, a new window slides in allowing you to select something. The selected value is passed back to the original screen.

Form embedded in a NavigationView.swift

import SwiftUI

struct ContentView: View {

    @State private var pickerSelectedIndex = 0
    var treats = Treat.demoTreats

    var body: some View {
        NavigationView {
            Form {
                Section {
                    Picker(selection: $pickerSelectedIndex, label: Text("Treats")) {
                        ForEach(0 ..< self.treats.count) {
                            Text(self.treats[$0].name).tag($0)
                        }
                    }
                }
            }.navigationBarTitle(Text("Treats for your cat"))
        }
    }
}

struct Treat: Identifiable {
    var id = UUID()
    var name: String
    var imageName: String
    var description: String
}

extension Treat {
    static let demoTreats = [
        Treat(name: "Fish Cakes", imageName: "FlyingFish", description: "Lots of fish, lots of cakes!"),
        Treat(name: "Mice Cream", imageName: "MiceCream", description: "Every kitty's favorite flavored Ice Cream"),
        Treat(name: "Croissant", imageName: "Croissant", description: "Seems like cats wouldn't like them, but they do!"),
        Treat(name: "Pancakes", imageName: "PanCakes", description: "They're cakes, but in the shape of a pan"),
    ]
}