Members of a Group cannot access the "members" tab (/group/group_id/members?destination=/drupal/web/admin/group) unless they have "Administer group members" permission which of course has other implications.
However, having the option to allow members to access the "Members" tab (/group/group_id/members) and view all the subscribed members of a Group without "Administer group members" permissions also makes sense.
Currently under General Group permissions, if a user has permissions as listed below:
Since the user can view the summary of any member, why not provide an overview of subscribed members and make the "Group membership" permissions consistent with the "General Group" permissions.
Create: "Access all members overview" permission.
Enabling this permission will display the "members" tab and by extension a list of all members within a Group.
Hence if a user has permissions as listed below:
Create: "Access all members overview" permission.
Active
3.1
Usability
I'd like to see this permission added as well.
As a workaround for now, you can edit the "Group Members" view (/admin/structure/views/view/group_members/edit/page_1) and change the access permission for the page to be "View individual group members".
Makes sense, tagging for next release.