As such, if you want to figure out who the true villain is in any movie set in the current day, looking for people who don't use an iPhone might give you a hint.

if you want to figure out who the true villain is in any movie set in the current day

条件状语从句。

who the true villain is in any movie set in the current day

条件状语从句里的宾语从句

 主干 ：looking for people who don't use an iPhone might give you a hint.

looking for people who don't use an iPhone 动名词短语做主干主语

who don't use an iPhone 是people 的定语从句

译文：

同样地，如果你想知道当今任何一部电影中真正的反派是谁，寻找不用iPhone的人可能会给你一个提示。