Create a Cloud Monitoring dashboard based on the BigQuery metric query/scanned_bytes

Create a Cloud Monitoring dashboard based on the BigQuery metric slots/allocated_for_project

Create a log export for each project, capture the BigQuery job execution logs, create a custom metric based on the totalSlotMs, and create a Cloud Monitoring dashboard based on the custom metric

Create an aggregated log export at the organization level, capture the BigQuery job execution logs, create a custom metric based on the totalSlotMs, and create a Cloud Monitoring dashboard based on the custom metric