Exact Medical situation name for Guided Meditation/Visualization to "Re-live a moment" There are lots of videos &amp; audios for Guided Visualization for particular things like forest, beach, sky etc.. But what should I exactly search to get result for "ReLive past Moment". Is there dedicated word in psychology?
Thank you.
Before I give the answer to your question, I must point out that pursuits into recalling past events through hypnosis etc. can lead to mixed results.  You can be lucky and gain true insight into a past event previously forgotten, but it cannot generally be relied upon in legal and forensic terms due to the risk of false memories being inadvertently implanted.  See my previous answer to a similar question and also this answer.

The term you are looking for is either


guided regression hypnosis, 
memory recall therapy or
memory recall training


All involve trying to get you to recall one or more specific events in such detail that you can remember them clearly.  The problem is that these methods have been found through research to cause False Memory Syndrome.  Although as with many pieces of research, there are opponents to the idea.