Getting AD groups and their users - powershell

Question

I've been trying to get a list of all the groups in our AD environment (with the description) and their members and output it to a CSV file. Ideally the users would be shown under their group. The script I've been trying to use is:
Import-Module ActiveDirectory
Get-ADGroup -Filter * -Properties Description |
Select-Object Name, Description |
ForEach-Object {
Get-ADGroupMember -Identity $_.DistinguishedName -Recursive |
Get-ADObject -Properties SamAccountname, Title, Department |
Select-Object Name, SamAccountName, Title, Department, DistinguishedName, ObjectClass
} | Export-Csv -Path c:\temp\ADGrab.csv -NoTypeInformation
The error I keep getting is as follows:
Get-ADGroupMember : Cannot validate argument on parameter 'Identity'. The argument
is null or empty. Supply an argument that is not null or empty and then try the
command again.
At C:\Users\j_kennedy_ta\AppData\Local\Temp\9\2898ceb2-a6cf-4fbf-9341-e651dad2145d.ps1:4 char:28
+ Get-ADGroupMember -Identity <<<< $_.distinguishedname -Recursive |
+ CategoryInfo : InvalidData: (:) [Get-ADGroupMember], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.ActiveDirectory.Management.Commands.GetADGroupMember

Answer 1

Without the nasty Select-Object and with group information in the CSV file:
Import-Module ActiveDirectory
Get-ADGroup -Filter * -Properties Description |
ForEach-Object {
# Store for later use
$groupName = $_.Name
$groupDescription = $_.Description
Get-ADGroupMember -Identity $_.DistinguishedName -Recursive |
Get-ADObject -Properties SamAccountname, Title, Department |
Select-Object Name, SamAccountName, Title, Department, DistinguishedName, ObjectClass, ` # Mind the gap
# Calculated properties with group information
#{ name = "GroupName"; expression = $groupName }, `
#{ name = "GroupDescription"; expression = $groupDescription }
} | Export-Csv -Path c:\temp\ADGrab.csv -NoTypeInformation