Hi Ahmad,To confirm, you are utilizing our Flex event type? If so, I would recommend utilizing Admission Items and the Session Association settings within the Advanced Settings tab of the Admission Item.
Essentially, create Admission Items to break out all their options: Topic 1, Topic 2, Topics 1 & 2. You can apply the correct price to each Admission Item. Then, by using the Session Association feature, you can associate the actual Session so that when an invitee selects their Admission Item, they automatically receive the correct agenda.Please let me know if you have any additional questions!Best,Danni