Exchange/Powershell - Add data to new column rather than joining - powershell

Question

I am trying to export list of users in mail enabled security groups to csv but want to have each member in a separate column rather than joining the existing column.
$Csvfile = "C:\SPOgroupmembers.csv"
$Groups = Get-DistributionGroup -Filter "Alias -like '*.spo'" -ResultSize Unlimited
$Groups | ForEach-Object {
$GroupDN = $_.DistinguishedName
$DisplayName = $_.DisplayName
$PrimarySmtpAddress = $_.PrimarySmtpAddress
$Members = Get-DistributionGroupMember $GroupDN -ResultSize Unlimited
[PSCustomObject]#{
DisplayName = $DisplayName
PrimarySmtpAddress = $PrimarySmtpAddress
Members = ($Members.Name -join ',')
}
} | Sort-Object DisplayName | Export-CSV -Path $Csvfile -NoTypeInformation -Encoding UTF8 #-Delimiter ";"
This is how it currently outputs:
DisplayName
PrimarySmtpAddress
Member
Test.SPO
Test.SPO#test.com
User1,User2,User3
This is what I am trying to achieve:
DisplayName
PrimarySmtpAddress
Test.SPO
Test.SPO#test.com
User1
User2
I may be missing something simple but any help would be appreciated

Answer 1

If you want to export the data where each member has it's own row, which in my opinion, would be the proper way to do it, you can have an inner loop to create a new pscustomobject per member of the Group:
Get-DistributionGroup -Filter "Alias -like '*.spo'" -ResultSize Unlimited | ForEach-Object {
foreach($member in Get-DistributionGroupMember $_.DistinguishedName -ResultSize Unlimited) {
[PSCustomObject]#{
DisplayName = $_.DisplayName
PrimarySmtpAddress = $_.PrimarySmtpAddress
Member = $member
}
}
} | Sort-Object DisplayName | Export-CSV -Path ....

Answer 2

The simplest way to construct a [pscustomobject] dynamically is to construct an ordered hashtable first - which is easy to extend iteratively - and cast it to [pscustomobject] when done.
However, in the context of creating CSV output, you need to commit to a fixed number of properties (columns) ahead of time - if feasible[1]; e.g.:
$maxMembers = 10 # <- adjust this number to the max. count of members you expect
$Groups | ForEach-Object { ...
# ...
# Initialize an ordered hashtable with the static entries...
$oht = [ordered] #{
DisplayName = $DisplayName
PrimarySmtpAddress = $PrimarySmtpAddress
}
# ... then iteratively add the Member1, Member2, ... entries
foreach ($i in 1..$maxMembers) {
$oht["Member$i"] = $Members[$i-1]
}
# Convert to a [pscustomobject] and output
[pscustomobject] $oht
} | Sort-Object DisplayName | Export-CSV -Path $Csvfile -NoTypeInformation -Encoding UTF8
If no max. member count can / should be assumed, consider denormalizing the data by using a single member column combined with creating a separate row for each member, as shown in Santiago's helpful answer, which is unquestionably the better approach for subsequent programmatic processing of the data vs. the multi-column approach you're seeking, which may be simpler to grasp for the human observer.
[1] That is, you need to know how many members a group can have at most. You could even try to determine that count programmatically, ahead of time, but either way the resulting number may be too large to be practical.