Hi. Bit of a disclaimer, I have never actually used ServiceNow as part of my job, but I am a maintainer on the ServiceNow collection ATM.
Would you be able to break the process up, for example
Step 1: playbook triggers a ServiceNow change request that requires managerial / CAB approval, then ends
Step 2: Manager/CAB approves, and ServiceNow uses a callback/webhook to trigger the next playbook
Another idea would be to have a job that runs every X minutes, hours, whatever and uses the change_request_info module to check for tickets that have exited the approval stage. Then that job could kick off the next job(s), depending on what tickets are ready