If you want to see a great documentary on a cult, Holy Hell is hard to beat. https://www.imdb.com/title/tt5278464/
It was filmed by a member while inside the cult. He had a degree in film making and all the equipment. He quit the cult later and then made the film. The cult is still going, although smaller and he confronts the leader at the end of the film. They guy is cryptic and does not offer much.
The climax though, is when they show a ritual where the leader goes off in the woods and invites the members to come to him one at a time and he will give the secrets to the universe. Each one comes back glowing with happiness. Of course they can’t explain it. A few don’t get to go, so really it was a way of controlling the group. But still, I would love to know what the hell the guy did.
Wikipedia gives a few more details, like how the cult leader was a porn star at one time. What it showed me is, if a small group of people want to do something, like build a mansion in California and put on hippie plays (to no audience), they will figure out a way to do it. As cult leaders go, this guy is pretty smart. He got to where he had a following that did whatever he wanted, and he didn’t push it too far, so the group never completely collapsed.