In the movie "The Boy in the Striped Pajamas" Karl was telling that his father had left him and went to Switzerland.
What was the reason behind leaving his son and moving away.
With apologies to purists for quoting from Wikipedia here:
One day, Elsa discovers the reality of Ralf's assignment after Lieutenant Kurt Kotler (Rupert Friend) lets slip that the black smoke coming from the camp's chimneys is due to the burning corpses of Jews. She confronts Ralf, disgusted and heartbroken. At dinner that night, Kotler admits that his father had left his family and moved to Switzerland. Upon hearing this, Ralf tells Kotler that he should have informed the authorities of his father's disagreement with the current political regime as it was his duty.
So, Kotler's father moved to Switzerland to avoid the consequences of his political views.