in a diagram-table there are two fields, which should be works together. If table field largest_case is empty, Location-field should be also empty. If largest_case have a value, Loacation have a value.
use an if statement. But this is not very clear, you need to elaborate a little.
if (len(largest_case)=0,' ',Location_field ) as Location_field
if(len(Location_Field)=0,' ',largest_case) as lagest_case
may be you looking for this.
if(len(trim([largest_case]))=0, '', [Location-field]) as [Location-field]
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