title: Add a button to tab bar controller scene in storyboard
body: <p>I am trying to design a application that has a tab bar on the bottom and two buttons on the top of the screen. </p>
  
  <p><a href="https://i.stack.imgur.com/avj6N.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/avj6N.png" alt="enter image description here"></a></p>
  
  <p>However, I'm not able to drag a UI Button onto the Tab Bar Controller Scene in storyboard on Xcode. I'm able to add buttons, search bars, etc to the view controller of each tab bar item, but not the original home screen. Why is that?</p>