There is a dropdown we like to create without showing the null values, The dropdown is based on the activity column, so some activities have null values in them.
If I filter with: FILTER ACTIVITY_TABLE.COLUMN IS NOT NULL;
I see the null value drop to the bottom:

I have tried additional filters like:
FILTER ACTIVITY_TABLE.COLUMN !=;
FILTER ACTIVITY_TABLE.COLUMN != ;
FILTER ACTIVITY_TABLE.COLUMN !=-;
Best regards,
Paul Velthuis