I understand the values of belief and revenge and how they interplay, just unsure about how to link it to disruption to accord in the following as relates to Hamlet?
Revenge tragedy progresses from disruption to accord while dramatising the interplay of belief and revenge.
accord: a settlement of differences, as between nations
[ via Old French from Latin ad- to + cord-, stem of cor heart] (Collins Dictionary)
Accord has one definition that means to come to a settlement of differences after a dispute. The example is an accord between nations that have been at war or in a disrupting dispute of some other sort.
This applies to revenge tragedy, and specifically to Hamlet, in that there is a disruption of harmony or of status quo (things as they have been) that brings about disputes or worse. Accord is reached when the tragic hero finds some way to resolve the dispute. In Hamlet's case, the resolution involves the deaths of the major characters, including himself.