Based on the Microsoft SC-300: Identity and Access Administrator Official Study Guide and Microsoft Learn module "Manage access reviews in Azure AD" , when creating an access review with the setting Reviewers: Members (self) , each user who is a member of the target group is only allowed to review their own access , not the access of others.
Here's how the logic applies in this scenario:
* The scope of the access review is set to Everyone , meaning both internal members and external (guest) users within Group1 will be included in the review.
* The reviewers option is configured as Members (self) - this setting instructs Azure AD to send review tasks to each user so they can attest to their own need for continued group membership.
* Therefore, User3 (a Guest user) will receive the review task to confirm or deny their own access to Group1.
* User1 and User2 , though they are members and User1 is the group owner, will not review User3's access because "Members (self)" does not delegate review authority to other members or owners - it only applies to individual self-assessment.
Microsoft documentation explicitly clarifies:
"When you select Members (self) as the reviewer type, each user reviews only their own access. Owners or administrators do not approve or deny access on their behalf." Hence, in this scenario, only User3 can perform the access review for their own membership in Group1.