'How to make alert fire only for subscription and not for resources under it?

I had created an alert with a specific subscription as 'scope'. The condition of the alert was

Whenever the Activity Log has an event with Category='Administrative', Signal name='Create role assignment (roleAssignments)'

But the alert was getting fired even when a new role was getting added to any resources under the subscription. I wanted it to fire specifically when a new role is added to the subscription exclusively , how to make it happen?



Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source