BuddyPress.org

This will work, I’ve used the right hook this time, and tested myself to make sure it’s working:

function venutius_display_member_role() {

    global $members_template;

    // This is a confirmed group member.
    if ( $members_template->member->is_confirmed )
        echo '<p>Member</p>';

    // This is a group moderator.
    if ( $members_template->member->is_mod )
        echo '<p>Mod</p>';

    // This is a group admin.
    if ( $members_template->member->is_admin )
        echo '<p>Admin</p>';
}
add_action( 'bp_group_members_list_item_action', 'venutius_display_member_role' );