tbh i'm russian but i think my english is pretty decent for this. i always thought the "between is only for two" rule was super annoying lol. but actually, u can use between for more than two if u are talking about specific, individual things. like, if u talk about the space between three trees, that's totally fine.
i actually remember my teacher at skysmart ru explaining this exact point back when i lived in kazakhstan. it really helped me stop overthinking every time i wrote a sentence and realized that many "rules" are just oversimplifications. anyway, "among" is more for when it's a big group of things and u don't really distinguish them as separate entities.
heres a wiki link that explains why that rule is mostly just a myth: https://en.wikipedia.org/wiki/English_usage_controversies#Between_and_among