Here is the business case, if the customer clicks the campaigns through a paid search/social/affiliates etc. and lands on AA website and data reports in "AA-report-suite" then user clicks on CTA button or links from AA website then customer goes to BB website which data sits in BB-report-suite. how we can recognise the users are clicked through campaigns in BB-report suite?
It might not be the best possible option, but we can extract raw data for the traffic in AA report suite with the visit referrer. Thereafter, the raw data can be extracted from the traffic in BB report suite with the visit referrer column. And correlate data from AA report suite and BB report suite to get some details. Another option would be to go the VISTA rule route and discuss the possibility with the Adobe's Engineering Services team (via your CSM).