The first sentence is fine ("the top" referring to a position of power or authority -- or feasibly it could have a literal meaning, referring to the top of a mountain, say). The second sentence is not an idiom that I have ever heard. It would not mean anything to me (except literally, referring to the accommodation in a building).
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Mr. Tom
The intended meaning of the second sentence is:
in any field, films or games, media or politics, no two people can be (equally) most famous or most popular--it has to be one.