"Montrer quelque chose à quelqu'un" means "to show somebody something" or "to show something to somebody".

Can I say "montrer quelque chose quelqu'un", as in English?

And what about persons, can I say "te montrer à moi" or "me te montrer"?

The problem seems to be that "me" and "te" have the same forms for direct and indirect object, so you can not distinguish which one is where.