title: BigQuery - Cannot join on repeated field
body: <p>Im trying to create a table that is 1 column with each row being a new date between 2 separate dates. The query works fine until I add a where clause that contains a subquery ie. NOT IN (SELECT ....). It works fine if I do something like NOT IN (TIMESTAMP('xyz')). </p>
  
  <p>I keep getting an error saying "Cannot join on repeated field t2.f0__group.SomeDate"</p>
  
  <p>I have no clue why this is happening. Also Im fairly new to BQ so if there is an easier way to do this please let me know. Thanks</p>
  
  <pre><code>SELECT SomeDate FROM
  (
    SELECT DATE_ADD(Day, i, "DAY") SomeDate
    FROM
    (
      SELECT '2020-01-03' Day
    ) T1
    CROSS JOIN
    (
      SELECT
       POSITION(
         SPLIT(
           RPAD('', DATEDIFF('2020-01-30','2020-01-03') * 2, 'a,'))) i 
      FROM
      (
        SELECT NULL
      )
    ) T2
  )
  WHERE SomeDate NOT IN (SELECT OtherDate FROM 
    (
      SELECT TIMESTAMP('2020-01-04 00:00:00 UTC') AS OtherDate
    ),
    (
      SELECT TIMESTAMP('2020-01-06 00:00:00 UTC') AS OtherDate
    ),
    (
      SELECT TIMESTAMP('2020-01-08 00:00:00 UTC') AS OtherDate
    )
  )
  </code></pre>