Calculating Revenue Value for Waybills Created in Previous Month but Delivered In Current Month

[Henry_Laser]

Good morning All

I am fairly new to Qlik Sense. I was tasked to do a calculation which I will describe below, but I have not yet found a solution that works.

I have to create a filter, whereby our team only selects a month (ex April) and then they will be able to see Revenue value for the current selected month,  the revenue for waybills that were created in the previous months but was only delivered in the current month as well as the revenue for waybills created in the current selected month but not yet delivered. 

I have done a mapping table to combine the waybill created date as well as the waybill delivery date. I can see the dates as this works fine. However, I am currently struggling with the correct syntax to calculate the Revenue for the waybills that were created in the prior months  but was only delivered in the current selected month. I have tried the below but I have yet to find a solution: 

Sum({<CreationDate = {">=$(=MonthStart(Max(CreationDate)-1))<=$(=MonthEnd(Max(CreationDate)-1))"}, DeliveryDate = {">$(=MonthStart(Max(DeliveryDate)))"}>} Revenue)

Thank you very much in advance for the assistance.

Kind Regards

Henry