title: Clausing a nested BigQuery doesn't as expected
body: <p>I am basically trying to query a column called hits.CustomDimension.index , so I had to nest multiple times in order to be able to access the data. I am trying to filter so it only shows up the rows where hits.CustomDimension.index = 16 with the query below, but its returning all of the CustomDimension rows for any observation which has CustomDimension.index = 16 somewhere.
  Not sure what I am doing wrong? As you can see in the image I added, still all the custom dimensions where customDimension.index = 16 are appearing, i only want that one flattened.</p>
  
  <pre><code>SELECT * EXCEPT(hit, hits)
  
  FROM ***,
  
  UNNEST(hit) h
  
  CROSS JOIN UNNEST(customDimensions) cd 
  
  WHERE cd.index = 16 AND timeOnSite IS NOT NULL
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/m057B.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/m057B.png" alt="enter image description here"></a></p>