How can the organization achieve this?
The organization should create each user in a separate region so that they have their own URL to login
The organization should create a separate login ID but give the IAM users the same alias so that each one can login with their alias
It is not possible to have the same login ID for multiple IAM users of the same account
The organization should create various groups and add each user with the same login ID to different groups. The user can login with their own group ID
Explanations:
Creating users in separate regions would not allow them to share the same login ID, as login IDs are unique per AWS account regardless of region.
Each IAM user must have a unique login ID. An alias does not change the requirement for unique IDs; it simply provides an alternative name for a user.
AWS IAM requires that each user has a unique login ID within an account, so it’s not possible for multiple IAM users to share the same login ID.
IAM groups do not provide a way to share login IDs among users. Each user must still have a unique login ID, regardless of group membership.
I compute that the answer is:
It is not possible to have the same login ID for multiple IAM users of the same account