"The one who lives above the bank is playing among the trams and taxis."

Translation: Az játszik a villamosok és a taxik között, aki a bank fölött lakik.

[Krisbaudi]

Az........., aki........... Does it really fit together in one sentence? Aki is only for persons, but az (that)? I need help please, to understand that.

[Shamarth]

Normally it's not polite to refer to people with "az", but this structure is fixed, there's nothing you can substitute "az" with.

[vvsey]

Yes, this is perfectly normal, this is how you have to do it. Occasionally you can enhance it like this:

"Az az ember......., aki ......".

But it is optional. And the "az" is still there.