Bruce JDC Blog

# get group members recursive, ignored circular nested group
param(
[parameter(mandatory=$true,position=0)]
$group
)
 
$Global:members = @()
$Global:list_members_extended = @()
 
function mygroup($name) {
            foreach ($groupe in (get-distributiongroupmember $name | group-object RecipientType)) {
                        if ($groupe.name -eq "MailUniversalDistributionGroup")     {                     
                                               $groupe.group | foreach {
                                                           if ($Global:list_members_extended -notcontains $_.name) {
                                                                                  $Global:list_members_extended += $_.name
                                                                                  mygroup $_.name
                                                           }
                                               }
                        } else {
                                   $Global:members += $groupe.group | select alias
                        }
            }         
}
mygroup $group
return ($members)