Movie is about a guy who lives in a lie. he has no job. He spends his time at the park while telling his family that he is a bank teller. He earns money by taking a loan from his frineds and family and lies to them that they are investing money and they will get much more later. Last scene, he is at the park, and a guy next to him speaks exactly like him and tells same lies as he did before. All in all his life is one big lie.
“Timeout”? https://www.imdb.com/title/tt0279065/
If you’re sure the character works in a bank, it’s probably La Vida de Nadie (Nobody’s Life, 2002), which is another adaptation of the same events.