title: power BI need to find missing values in table from a reference list for each group of values
body: <p>I need to find where values are missing in a table from a reference table and then create an output with the missing values. Here is an example of what I'm trying to do.</p>
  <p><a href="https://i.stack.imgur.com/CKyue.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CKyue.png" alt="enter image description here" /></a></p>
  <p>Does anyone have any idea how to do this.</p>