Case view - Button visible/not visible

Hi All ,

Have a requirement where on case form view, a button "Manager Approval" need to be hidden when location is empty.

For this I created a UI action on Case table where I am checking for location if nil() in condition. This works as expected where if location is blank on case, the button "Manager Approval" is not visible and when a case contains location "Manager Approval" button is shown.

The requirement is when the user selects location on the blank location field, the button "Manager Approval" should re-appear. Please guide on how to achieve this.

TIA