If statement for dimension, exclude fields, handle nulls

[evansabres]

I have a field, 'Group' that I am using as a dimension. I am excluding certain values from the dimension, such as 'ABC', 'DEF', by =IF(Not Match(Group, 'ABC', 'DEF), Group) however, would there be a way to introduce more logic to rename fields that are blank or null?

[evansabres]

This works for the structure of the equation, however as the field is Null, it is still showing as Null/Blank in my table.

[sunny_talwar]

May be try this

=If(Not Match(Group, 'ABC', 'DEF) and Len(Trim(Group)) > 0, Group, 'No Preference')

or this

=If(Len(Trim(Group)) = 0, 'No Preference',
 If(Not Match(Group, 'ABC', 'DEF), Group, 'No Preference'))