title: NavigationView title doesn't appear when the views are in TabView in SwiftUI
body: <p>I have two Views and each of them contains NavigationView with title. I have created a TabBar View which also has a NavigationView on it. </p>
  
  <pre><code>struct TabbarView: View {
  var body: some View {
      NavigationView{
      TabView {
          MainContentView()
              .tabItem {
                  VStack {
                      Text("Main")
                  }
          }.tag(0)
  
          SearchContentView()
              .tabItem {
                  VStack {
                      Text("Search")
                  }
          }.tag(1)
      }
      }.navigationBarBackButtonHidden(true)
      .navigationBarHidden(true)
  }
  </code></pre>
  
  <p>}</p>
  
  <p>I have tried hiding the navigationBar for this view but that doesn't work. Only the navigation bar of this view appears. </p>
  
  <p>This is <code>MainContentView()</code></p>
  
  <pre><code>struct MainContentView: View {
  
  var body: some View {
      NavigationView {
          Text("Some Content View")
          }
      .navigationBarTitle("Travel")
  }
  </code></pre>
  
  <p>}</p>
  
  <p>Any idea how to go about this. Thanks!</p>
  
  <p>Update:
  Basically when I tap on a <strong>Log In</strong> Button, I am passing TabBarView() through NavigationLink. </p>
  
  <pre><code>   NavigationLink(destination: TabbarView()) {
                          HStack {
                              Text("Log In")
                          }
                          .padding()
                          .frame(width: geometry.size.width - 40, height: 40)
                          .foregroundColor(Color.white)
                          .background(Color.blue)
                          .cornerRadius(5)
                  }.padding(.bottom, 40)
  </code></pre>
  
  <p>In doing that, it shows the TabbarView() with child views this is what I see:
  The space above "Travel" (navigationBarTitle of the childView) is the navigationBar of the tabbar since I am pushing it into navigationStack. </p>
  
  <p><a href="https://i.stack.imgur.com/lVHnd.png" rel="noreferrer"><img src="https://i.stack.imgur.com/lVHnd.png" alt="enter image description here"></a></p>