At some point I accidently dragged a main directory into another directory. How to I get it out? I'm able to move the directory to another directory but not to the main/first level again.
You should be able to do that, what exactly are you doing to move it to the Top Level? All you should need to do is drag the folder from it's suvfolder and place it between two othe folders or the top level and the first folder, that works for me. Note that when you drag the folder betrween two others you should see a horizontal blu liner that shows you where the folder will be dropped.