Get nested Active Directory group members

function Get-ADNestedGroupMembers { [cmdletbinding()] 
param ( [String] $GroupName )        
     import-module activedirectory 
$Members = Get-ADGroupMember -Identity $GroupName $members
 | % {     if($_.ObjectClass -eq "group")
{         Get-ADNestedGroupMembers -GroupName $_.distinguishedName     } else
 {    
     return $_.distinguishedname     } }             }