Excluding members in DataGridDefinitionBuilder

Summary

How do you remove / exclude members from list with DataGridDefinitionBuilder

Content

I am trying to do the equivalent of an Except / Exclude, replicating what you can do on the forms with an "Add Exclusion". I've tried to do something like these, but the desired excluded members are still included. 

• mygridbuilder.addRow(['Grades'],[ ['ILvl0Descendants(Grades)']-['Grade 1'] ])
• mygridbuilder.addRow(['Grades'],[ ['Except(ILvl0Descendants(Grades),[Grade 1])'] ])

The first attempt runs but does not exclude the member, the second raises an error when run. 

Has anyone implemented this?

 

Version

20.02.80