How to filter assignable user list based on the current user?

[AlekseyStrelnik]

We have two user groups Group X and Group Y with customers (clients) from organization X and Y respectively. In one project I need to split assignable user list for different customers:

1. If current user is in Group X, then assignable users are User1, User2

2. If current user is in Group Y, then assignable users are User3, User4

[Nic Brough -Adaptavist-]

You can't do this.  The assignable user is the list of people who have permission to be assigned issues, which has nothing to do with other users.

[AlekseyStrelnik]

Thank you! So what can you recommend to hide some project users from clients?

[Nic Brough -Adaptavist-]

As I said, you can't do this.