Filter option for custom reports in Google Analytics Source

[iosonodenis]

Hello,
I am trying to build a filtered custom report for the GA Univeral Connector. I am requested to also export data for the CD1 and I think I have too much cardinality (exported data does not match), so I am considering to build several custom reports, one of each channel grouping.

However filtering like this returns 0 rows in bigquery. Does the filter functionality works?

[
  {
    "name": "organic_data",
    "dimensions": [
      "ga:date",
      "ga:sourceMedium",
      "ga:hostname",
      "ga:dimension1"
    ],
    "metrics": [
      "ga:sessions",
      "ga:users",
      "ga:pageviews",
      "ga:goal5Completions"
    ],
    "filters" :[
      "ga:channelGrouping=Organic Search"
   ]
  },