Convert data in an outline to Pan X

How is this link made? I feel like I’m missing an obvious tool or concept. I don’t see how Lookup( would work since I am only trying to link each record in database2 with a record in database1. I could manually enter the unique-in-database1 value, but I’d like to select it from the values in database1 (and, more advanced, add a record to database1 when the currently entered value in database2 does not exist in database1).

@admin seems to indicate (and now, while I waited for the forum bot to let me post this reply, helpfully repeated in this thread) that links like this are done as needed. Using the tutorial Checkbook example — how would one set up a database of Categories, and how would that be linked to the Checkbook database?

This is moving off topic. Should I start a new Topic on “linking” databases?