title: Add an "ALL" item to list of items in Parameter drop down
body: <p>I am experimenting in PowerBI Paginated Reports and find the experience to be nearly identical to SSRS development.</p>
  
  <p>So I'm bringing back a dataset borrowed from an existing Power BI solution.  I'd like to build a parameter to filter the results.  So I create some DAX to read just the unique combinations of two fields from the dataset for value and display.</p>
  
  <p>I'd like to replicate an old trick where in SQL I would just union on a row with fields like "All" or "No Filter".  While I'm able to construct this analog in DAX Studio, it doesn't seem to be migrating well to Paginated reports.</p>
  
  <pre><code>EVALUATE
   (
      UNION (
          ROW ( "Plant Number", "ALL", "Plant Name", "All Plants" ),
          SUMMARIZE ( 'PLANT PR1', 'PLANT PR1'[Plant Number], 'PLANT PR1'[Plant Name] )
      )
  )
  </code></pre>
  
  <p>That's the DAX that I can use in DAX studio, but when I put it in Paginated Reports as a data source for my 'Plant' Parameter, I get a bunch of nulls in the dropdown.  Any Ideas on how I could improve this to work in Reports?</p>