I'm working with a REST API that returns doubly-nested JSON (think: a top-level array of objects, each containing a nested array, which itself contains another nested array). Celonis splits this correctly into three separate tables, and the parent key from the top level propagates fine into the first nested table. The problem is that it stops there.
The second-level nested table has no reference back to the top-level parent. The intermediate ID that's available at that level isn't unique (it's a type identifier that's the same across all top-level records), so I have no way to join the second-level table back to a specific top-level record without getting a cartesian product.
The root issue as far as I can tell: in the Connector configurator, you can only choose from fields that exist in the API response as Primary Key. The propagated parent key that Celonis adds to the first nested table isn't available as a selectable column when configuring the second nested table, so there's no way to define a composite PK that would carry that ID further down.
Is there any configuration option (Response Rules, or anything else) that would allow injecting the parent ID into second-level nested records? Or is this a known limitation?