If the dreamer is doing the hiding, there is a part of him that is “hidden,” even from him, that perhaps needs to come to the surface and be looked at.
If the dreamer hides an object from someone else, then he is concealing something that perhaps needs to be revealed.
If the dreamer is searching for someone or something, there is something missing, either an idea or an actual object, that she needs to find and make use of. Other symbols in the dream could reveal exactly what that is.
Astrological parallels: Pluto, Scorpio Tarot parallel: The Moon