I'm not sure I understand your request, anyway, here is my approach.
Edit relationships and custom==> add ==> and link "Month" and "Month and Year"
Put Budget from primary data source which is blue.
Change measure to average.
Put "Ad server clicks" from secondary data as "sum".
One more thing.
I sorted "Month" with calculated field because it's sorted alphabetically.
budget_actual_9.2.twbx 6.1 MB
Thanks Shin for your response! I think that fixed it. I checked the Tableau display against the raw data and everything looks correct! Very much appreciate your quick reply!
You are welcome!.