When you're editing a document, the navigation / table of contents is displayed as abstract bars on the left side of the screen:
This is so it's not a distraction and you can focus on the content on the screen. If you hover over the bars, you'll see the actual text:
To move any section or policy, just click the one you want to move within this view, hold, and drag up or down. Once you release the mouse button to drop the section/policy, your view will update to reflect the new order.
If you grab a chapter header section, the entire chapter will move as one. Drag and drop above or below another chapter to move it. You can also hold CMD (mac) or CTRL (windows) while you click and drag a chapter header if you want to move just the chapter header.