How to Update a field in a nested table?

[Tuuli]

Hi all, 

I'm currently trying to update a field in an universal analytics sessions table. The table is nested, so a simple update query is not working, I was also not able to update the field after unnesting the structure.

The table structure is documented here: https://support.google.com/analytics/answer/3437719?hl=en

More specifically, I need to update the field 'hits.eventInfo.eventLabel' , only the rows where 'hits.eventInfo.eventAction' and 'hits.eventInfo.eventCategory' have a certain value.

My query is the following:

UPDATE `my_database.DataDel.ga_sessions_*`

SET hits = ARRAY(

  SELECT AS STRUCT * REPLACE(

      (SELECT AS STRUCT

        eventInfo.eventCategory,

        eventInfo.eventAction,

        CASE

          WHEN eventInfo.eventLabel LIKE "%@%" THEN "removed"

          ELSE eventInfo.eventLabel

        END AS eventLabel,

        eventInfo.eventValue

      ) AS eventInfo

      FROM UNNEST(hits.eventInfo) AS eventInfo

      WHERE eventInfo.eventAction = 'abc_action'

      AND eventInfo.eventCategory = 'xyz_category'

    )

    AS eventInfo)

   AS hits

WHERE TRUE;

Could anyone help me to refine this query or let me know if an update  of the field 'hits.eventInfo.eventLabel' in a nested table is possible?