The left dropdown button consists of "All Files", "All Text Files", "Directories", "Image Files", "Script Files" and "Sound Files". This button will show you just the files you request in your main (root) area, or in any directory you choose. Use the right dropdown button to choose the directory of which you want to view the contents. Then click the "Relist Directory" button, and you will be in the directory you want, looking at just the file types you want to see.
For example, if you have a "puppies" directory consisting of html pages, sound files, and images, and you just want to see what images you have in that directory without scrolling through all the other files, use the "Relist Directory" feature to do that. In this example, you would click the left dropdown button and click on "image files".. then in the right dropdown button, click on it and scroll down to the "puppies" directory (if you type the first letter of the directory and it will jump down to the first occurrence of that letter), now click the "relist" button and you will be taken to the "puppies" directory and you will only see the image files in that directory. If you then want to view all the files in that directory, just go up to the top of the page and click the left dropdown button again, click on "All Files" and click the "relist directory" button, and all the files in that directory will be listed.
This is also a fast way to get from directory to directory, just use the right dropdown menu and click your way from one directory to another. NOTE: Make sure you use the "relist directory" button for navigation, do not use the "energize" button. The "energize" button is only for use with the beamer.