You know the drill: button 3 (usually right click) to unfold/fold directories (the ones marked with a '+'. Same click on a regular file sends it to the plumber, so default behaviour will be to open it if it's text. Button 2 (middle click) on Win or Xplor commands opens a new win (or a new xplor respectively), by default at the same root directory as their parent. However, they make use of chording 2+1: just position your cursor wherever you want in the tree, then button 2 on Win or Xplor, hold it, and at the same time press button 1. Tadaaa! behold the chording magic! Enjoy!