Automation Lite: how do I extract added value from a field change in multi-value field

[Kevin Cheng]

My case:

In FixVersions field, user can enter one or more values at different time of a JIRA ticket.

What I want is to trigger the automation to create a subtask which I only extract the added FixVersion in the parent ticket and use that for the title and FixVersion in the subtask itself.

For now, I am only able to extract the entire list of value and it is being used for the title, but I do want separate subtask for each FixVersion.