Get-Adgroupmember for all groups

I have test group, user group, admin group in an OU, and I'm trying to get all members listed in all the groups. when I run the following code, I get "The size limit for this request was exceded". Is there a workaround for this error?

$Groups = Get-ADGroup -Filter {GroupScope -eq 'Global' -and Members -ne "NULL"}
      $Users = foreach( $Group in $Groups ){
      Get-ADGroupMember -Identity $Group | foreach {
        [PSCustomObject]@{
            Group = $Group.Name
            UserName = $_.SamAccountName
    }
 }
}
$Users | Export-CSV C:\scripts\groups.csv -NoTypeInformation   

Thanks very much

Try using Get-ADObject instead of Get-ADGroupMember to perform your query:

Get-ADGroup -LDAPFilter '(&(groupType:1.2.840.113556.1.4.803:=2)(member=*))' |
    ForEach-Object {
        $filter = '(memberof={0})' -f $_.DistinguishedName
        foreach($obj in Get-ADObject -LDAPFilter $filter -Properties samAccountName) {
            [PSCustomObject]@{
                Group    = $_.Name
                UserName = $obj.SamAccountName
            }
        }
    } | Export-CSV C:\scripts\groups.csv -NoTypeInformation