RawQuerySets allow you execute raw sql, 

but it's not possible to combine raw calls with regular ORM calls (filter(), order_by(), etc..). 

Since the purpose of django-filter is to validate and construct those ORM calls, 

RawQuerySet is just incompatible.

PropertyDescriptorCollection propCollection = TypeDescriptor.GetProperties(Question.GetType());

PropertyDescriptor descriptor = propCollection["Element"];

​

BrowsableAttribute attrib = (BrowsableAttribute)descriptor.Attributes[typeof(BrowsableAttribute)];

FieldInfo isBrow = attrib.GetType().GetField("browsable", BindingFlags.NonPublic | BindingFlags.Instance);

//Condition to Show or Hide set here:

isBrow.SetValue(attrib, true);

propertyGrid1.Refresh(); //Remember to refresh PropertyGrid to reflect your changes