Greetings! I have the next issue
User Picker (multiple users) A and User Picker (multiple users) B
I need to create a rule, that will update A, if user add changes to B
Example:
In customfield A we have user 1, user 2, user 3, user 4
If add a values user 2, user 1, user 4 in customfield B, remove these users from customfield A.
Problem:
I can remove users from customfield A by next rule

Smartvalue StudentId
change customfield A json
The rule works correctly if you add one user, but if you add several at once, the rule gives an error.
I try to solve the problem through For each, but it doesn't work
Please, tell me, how to solve my problem ?