Spiritually, to be undoing something suggests we are trying to reverse a process. This action is not always negative in that we recognize that a situation was better previously. We often recognize through the medium of dreams that an action will have unforeseen circumstances. To be undoing a knot or tangle suggests the necessity to sort a problem out. Pragmatically, when matters in everyday life have taken a turn for the worse, we may dream of undoing or loosening a stuck object to allow matters to move more smoothly. You might also like to consult the entries for Knot and Tangle.