As of version 22.3, only L1 and L2 Proactive Service Resolutions (PSR) use cases are supported.
Please refer Integrating with BMC Helix ITSM for more information on the details of these use cases.
PSR L3 with Helix ITSM i.e. having to show the Service impacted mapped to the incident created is planned in 23.1 release of the SaaS version.
Tracking ID for the same - DRF21-4656
As a workaround, users can manually edit the incident and map the impacted service. This will show the Probable root causal nodes on the screen too.
Example incident and probable cause nodes screen below:
