First of all, I would like to clarify that I'm asking at webapps.stackexchange.com community as suggested in this answer.
Well. This is a YouTube's live stream which was published by a content creator who recorded a multi-camera stream. So, if I'm not wrong, in theory we could switch to other people's webcam streams that were recorded too in that multi-camera stream.
I would like to know how can I see the other people's cameras/streams. Maybe can I add a parameter to the query of the YouTube video url?. If not, the how can I do it?. I don't see anything in the YouTube's user-interface to switch between recorded cameras during that live stream.
By the way, that is a "big" Spanish youtuber and in the comments section of that video there are thousands and thousands of people that are still writing comments (even right now, after the stream was finished many hours ago) with something that seems commands, like: "/cam2" - as a single, full commentary (and obviously those commands will not have any effect because they are literally publishing comments with that). And the same happened during the live chat in the live stream, thousand of people writing things like "/cam5" in the chat box, but when I wrote the command "/cam2" nothing happened. I don't understand if those users were just trolls, or they were trying random things to discover how to switch between cameras... asking himself the same question as I'm asking here in StackExchange.