Hi again @Mojo
we recently added a case about the functionality you are looking for, the where function.
You can now filter out data that have certain values. You can find here how to : CASE: where attribute
Further, I think that also answers your second question about the Test Percentage? You can call upon the variable in your for-loop.
If you need further help with that, don’t hesitate to upload your code so we can have a further look.
Kind regards
Sofie