Position of Hide Sidebar buton in SwiftUI

I was looking at the Apple Design Resources and saw a toolbar that looked like this:

where the hide sidebar button is inside the sidebar. However, using SwiftUI, I cannot find how to place it here at all times instead of next to the traffic light buttons. I can add an additional sidebar button before the title but I cannot remove the initial one by the traffic light buttons.

Is there any way to alter the position of this button? Thanks