Dialogflow CX scope helps you decide what set of actions CX can do based on the current state of the conversation. For example, only intent transition routes in the current page can fire (be invoked), and that’s because intent transition routes in the other pages are not in scope.

For a more detailed discussion, check out the Conditional routes with expressions chapter in my Dialogflow CX course.

The scope in Dialogflow CX is somewhat similar to candidate intents in Dialogflow ES.