How to access the expression library loaded in the parent pipeline from a child pipeline

@patan - are you simply trying to lookup the details associated with a “lookup” identifier? If so, skip the child pipeline altogether and use an In-Memory Lookup snap.

Here is an example that I think meets your needs.
Community 15256 - compare and get result_2023_01_03.slp (206.3 KB)

Hope this helps!