The original question had to be edited. Betrayal is a part of the narrative of both the novel and the narrative of the Haggadah. At some point, those who interacted with the Haggadah, a text of spiritual identity, had to deal with the issue of betrayal in their own lives. The relationship between Hanna and Ozren is one in which their pursuit of true feelings is one of betrayal through war. Ozren abandons Hanna emotionally when the reality of the war pierces his son's head with a bullet. Hanna betrays Ozren's wishes by taking his son's medical files to her mother, a surgeon.
Another example of betrayal would be in Father Giovanni's own understanding of self. Being a Catholic priest during the Inquisition in charge of burning books, his coming in contact with the Haggadah is an epiphany when he realizes the he, himself, is Jewish. He has betrayed his own identity in persecuting people like himself. His signature in the book is a tacit acknowledgement of this.
The scholarly betrayal that Werner and Ozren perpetrate on Hanna is another example of how passion and zeal can lead to betrayal in an alarmingly easy jump. Hanna recognizes this when they need her help to make the switch between both versions of the Haggadah.