Hello Roshani,

Use COE Access Control List (ACLs) Configuration to allow specific groups read or write access to HR cases under a specific COE.

Please refer below threads which might help you to proceed further:

https://docs.servicenow.com/bundle/orlando-hr-service-delivery/page/product/human-resources/concept/hr-service-categorization.html#configure-hr-coe-security

https://community.servicenow.com/community?id=community_question&sys_id=0a202ab7dbb8d41013b5fb24399619c7