how to find next performer in current task

Hello,

I think there is no out of the box solution. You can get assignees using "Me.Assignees" method, but only when you enter next step.

If allocation logic is not complex, you could implement additional rule that will short list available users based on same conditions as in allocation logic.

Or you can create Library rule that will return user ids and use it in current step to get potential assignees and in next step re-use library rule in allocation logic.

Martin