Formula to show a linked field is empty

Hi I am trying to group empty linked field but not sure which formula to use. Any help much appreciated. Thanks, Maria

Sorry that this has gone unanswered for so long. :frowning: Did you find a solution for this? If not, could you provide more detail about what you’re trying to do? You said initially that you want to group a field, but then mention using a formula. Those are two completely different tools, which is why I’m asking for a more detailed description that (I hope) will be more accurate.