Yes, why not? 

That could happen for the first time in 80 years if Brazil takes the title in Russia. That could happen with four guys: Neymar, Gabriel Jesus, Marquinhos and Renato Augusto. 

The last time players took gold olympic medals and world titles happened in 1938 when Italy beat Hungary 4x2 in France two years after the Berlin Games.

So, it's difficult. Really difficult. But it happens. For Brazil, the first part of the task is below. Enjoy.