In case if you are looking for solution of extracting the assignment of the Class data in SAP Using Standard Transaction, then below will be helpufl
Option 1: Use the Standard Code – CL6B – Object List
This gives you List of Classes and the objects ( materials) assigned to it
Option 2: Use the Standard Code – CL6BN – Object List
This gives you List of Classes and the objects ( materials) assigned to it in ALV Format.