Yes, the main navigation menu shows on the left side of the screen when you are in your tax return and using a full sized screen.
If you are using a tablet or mobile device, you may need to expand this menu by selecting the menu, or hamburger, icon in the upper left corner. See the image below.
If you are on a full sized screen, but don't see the left-side menu, you are on the home screen. You can open the return by selecting Pick up where I left off or Review.
If you have already filed your tax return, you can open your return again by selecting Add a State or Amend my return.