The Populations thing still confuses me at times. Here's the model we need.
We have a data extension GlobalContacts. The client will be adding records through the API. This data extension is set-up in an Attribute Group relating to (ContactBuilder) Contact by Subscriber Key. There is a second table that relates to GlobalContacts called Party.
We will use a filtered data extension from GlobalContact as an Entry Data Extension for Journey Builder. So my understanding is for those contacts to be injected they need to exist in a Population.
Here's where I'm confused...I think GlobalContacts should be the Population, but then I can't add it in an Attribute Group to relate to Contact and the Party Data Extension.
What am I missing? Am I going down the wrong path?