Users who are creating a scheduled report with multilevel pivot-type reports may note that the content from the scheduled email is empty when receiving the report. This is expected behavior.
Currently the reporting engine does not support scheduled multilevel pivot reports.
An enhancement request has been submitted for our product team for further evaluation to support this feature.
In addition to the noted information above, we have included our documentation which states that we are not supporting the feature at this time.
Provided here is the link to our documentation: https://docs.servicenow.com/bundle/kingston-performance-analytics-and-reporting/page/use/reporting/concept/c_MultilevelPivotCharts.html