How do i set up the logic for when a field value changes from x to y (Jira Automation Add on)

[Jamie]

I am struggling to find the right rule logic to get a notification, when a field value changes from X, to Y. 

Ie/ I would like the Service Desk Manager to get a notification if a ticket priority is changed from Priority 4, to a P1, or P2 ? 

I am using the add on 'Automation for Jira' 

Any help on what conditions/ triggers to use would be brilliant. 

[Malek Mhiri (er:sie/they)]

Would it solve the problem, if the priority changes to P1 or P2 or does it have to change from Priority 4 to P1 or P2?

[Malek Mhiri (er:sie/they)]

@JamieHave a look at this https://support.atlassian.com/jira-software-cloud/docs/smart-values-general/
The section about Changelog