The "View All Members" panel displays a paginated list of all members of the group. The default sorting is by the most number of posts. You may use the following links to change the sorting:

Most posts: Members with the most number of posts are listed first (secondary sorting is by Names; see below). This is the default sorting.

Most recent activites: Members with the most recent activities are listed first (secondary sorting is by Names; see below).

Names: Alphabetical order of the avatar names.