Triggering Inv Org specific NIRs where same item class is used across BUs/Inv Orgs

Dear All, We have an item which belongs to same item class and is globally managed....however, there are region specific attributes that needs to be maintained by the users from specific regions...these users have same job roles. While using NIR flow, it sends notifications to all users to all regions and does not restrict to users belonging to specific BU/Inv org. If anyone has come across such a scenario and designed a solution, please share with us.

Thanks in advance.