You have an Operations Center with two connected Masters.

Use the Pipeline build step with the remote path URL argument.

Use the cross team collaboration feature to publish a build notification and subscribe to that notice from Jobs that should run when the notification is published.

Broadcast an e-mail message from the Job on Master A and monitor the e-mail queue from Master B.

Use the "Trigger parameterized build on other projects" post-build step and specify the remote path as project name.

Use the trigger-remote-build CLI command and pass the Job URL as a parameter.