The TOPLIST menu is a list of the files in each window from top to bottom. If you select a file name from this menu, the window that contains that file will be made the top window. This is an excellent way to see what files you have in your windows, and to get a window on top quickly. It is especially useful for topping windows that are completely hidden by other windows.
The TOPLIST menu is also available inside any window (or outside all windows) by pressing the middle mouse button.
Try using this feature.