IMPORTANT
Don’t create a multisegment back button. The back button always takes the user to the current screen’s parent. If you think users might get lost without a multisegment control that displays a type of breadcrumb path, it probably means that you should flatten the information hierarchy.
Consider hiding the navigation bar when users want to focus on content. If you do this, be sure to let users restore the navigation bar with a simple gesture, such as a tap.
Maps with navigation bar (and toolbar) visible