SQL Resolution Scopes
This page lets you specify the data sources, databases and schemas that should be used to resolve unqualified ("short") names of database object in your SQL files.
You have two data sources, one for your production database and the other one - for your test database. The tables in both databases have the same names but slightly different structures. And you keep the SQL scripts for your production and test databases separately, in two different folders.
In such a situation, you'd map the folder with the production scripts onto the production data source, and the folder with the test scripts onto the test data source.
The other possibility would be to use the project mapping for your production data source and specify the mapping for the test scripts folder separately, or vice versa.