title: Validation for name range overlapping.
body: <p>I have this requirement, and I am at my wits end. Any idea how to get this working ? </p>
  
  <p>The field accepts a single value or a range to be part of the filter. Example of Ranges: "A-D", all the customers names with name starting with A, B, C or D; "SA-SP", all names starting with SA, SB, ..., SP; "MILG", all customer names with name starting with Milg;</p>
  
  <p>While adding account names, the ranges should not overlap. Example: A-Q, P-Z is not valid since P-Q range is overlapping.</p>