Hi ​@kellymremzilyb ,

When creating a SQL catalog item, to my knowledge you always refer to a physical data source. So to achieve what you describe, the following suggestions may be of help.

1. In the data source create a view that matches the logic of the intended nested catalog item (so a view that contains common table expressions or subqueries)
2. Define the nested logic in the SQL catalog item itself.

Kind regards,

Albert