Flutter Minimise container to see what's behind

I need some help with displaying a container above the navbar that you can minimise and see the map behind.

As you can see in this picture, the expanded container sits above the bottom buttons, which are the bottomNavigation of the page. How can I make such a container that when you minimise, you can still see the small line above the buttons to expand it back. Also, once the container is close, you can see map behind.

I am thinking of something like a bottom modal sheet but that shoots up from the bottom of the page, over the buttons. Also the modal bottom shit doesn’t minimise to only see the top all times.

Thank you for the help!