Multi user picker validator

[Giuseppe I]

Dear all,

I have a multi user picker field and a group named respectively "Field" and "Group".

I would like to check wether there is at least a user into "Field" who doesn't belong to "Group".

On the server version I wrote the following Groovy Script as validator in a transition and it works fine:

issue.get("Field")?.any{!ComponentAccessor.groupManager.isUserInGroup(it.name, 'Groups')}

Any suggestions on how to write it for the Cloud?

Thanks