Just getting GrowthBook setup for the first time and looking for a recommendation or specific documentation about how to handle cross-domain tracking. Each domain has its own GA4 property, if thats at all relevant.

depends a bit on how you set up the export to BigQuery - it is possible to set up multiple data sources

heres what i was thinking about doing... setup a "gbuuid" custom dimension in all GA4 properties then, use the gbuuid from GrowthBook SDK at the targeted domain as the value of that custom dimension across the current domain and all subsequent domains (passing the value in the URL). then, my understanding gets a little hazy. would i then be able to select that gbuuid custom dimension from the dropdown here to define users based on that value?