Thank you, now I m a step closer to the solution.
After creating the condition, I get an error:
"The input parameters of the "If_userID_contains_in_shift_userID_collection" operation contain invalid expressions. Correct invalid expressions for the input parameters of the "If_userID_contains_in_shift_userID_collection" operation."
I m unsure, how to correct it, since there is not any option as far from I see. Do you know where the issue could be?

Already helped alot, thank you!