I would like to know when Bojack horseman told Diana Nguyen, that was telling about closure, made up by Spielberg, it doesn't exist in real world. The only thing is to keep living forward. Can anybody please explain to me about Munich Olympic? Is this refer to Hitler and black guy who won?
While I haven't seen Bojack Horseman yet, you're definitely confusing things here.
Hitler's Olympic Games (1936) were hold in Berlin, not Munich.
The Olympic Games of Munich were held in 1972.
Considering mentioning [Steven] Spielberg, it's obviously referring to his movie Munich.
While looking for a full/direct quote I found a thread on Reddit about the same question.
But first the quote:
Closure is a made up thing by Steven Spielberg to sell movie tickets. It, like true love and the Munich Olympics, doesn't exist in the real world. The only thing to do now is just to keep living forward.
Also one of the comments probably answers your question as far as possible, so I'll just quote it here rather than trying to reword it myself:
I can't comment on what the Bojack crew was thinking, but I think it's pretty clear Bojack was talking about the film "Munich" - not the Munich Olympics themselves.
The film "Munich" was a pack of sensationalized made for Hollywood drama, while the Munich games themselves were obviously real.
Bojack wasn't denying the existence of the Munich Olympics as an actual historical event, just Steven Spielberg's dramatization of those events in "Munich."
But on another level, Bojack and his hero Secretariat constantly talk about running forward and ignoring the past, which doesn't exist anymore. On some level, Bojack may also be commenting on the fact that the past is the past and nothing is real except the present.