I've set up a Ens.Alert routing rule and would like to route alerts to different email groups based on business partner or alert group instead of relying on source config using Document.SourceConfigName. Is there a way to reference the business partner or alert group property in a routing rule?
You could write custom methods that query the source config item's properties for those values and call them from your routing rules. However, a more supportable solution would be to implement managed alerts, which will make those properties directly accessible to you in the Ens.Alerting.NotificationRequest object that's created from the Alert Manager business process.
See Configuring Alert Management in the documentation.