Formatting results from Powershell Select statement for ManagedBy Attribute in AD

Question

Right now I have a script that gathers user group names and the associated ManagedBy attribute using powershell.

$test = 'OU=example,DC=example,DC=test'

$test | ForEach {Get-ADGroup -Filter * -Properties ManagedBy -SearchBase $_ } |
Select Name, ManagedBy |
Sort -Property Name |
Out-File C:\test.csv

Results come through however the managedby attribute only supplies the FQDN(Distinguished Name) when all I need is the first CN in the result. In the case below, for example, all I need to display under ManagedBy is "testuser". No CN= or DC= distinguished name paths.

Name                                     ManagedBy                           
----                                     ---------                           
TestGroup_Modify             CN=testuser,CN=Users,DC=test,DC=domain,DC=com

I've tried a few things to use "-replace" with some formatting in the select but it ends up removing the first CN.

Select -Property Name, @{n='ManagedBy';e={$_.ManagedBy -replace '^.+?,(CN|DC.+)','$1'}}

results:

Name                                     ManagedBy                           
----                                     ---------                           
TestGroup_Modify             CN=Users,DC=test,DC=domain,DC=com   

Does anyone know a way of formatting these results or experience working with the ManagedBy attribute of a group? I was trying to figure out a way to somehow link the ManagedBy attribute back to the users SAMAccountName but was unsuccessful/lack the powershell experience. (I think it has something to do with the query retrieving ADGroups and not ADUsers) Thanks in advance for any help I receive on this.

The ultimate goal would be to achieve something like this:

Name                                     ManagedBy                           
----                                     ---------                           
TestGroup_Modify                         testuser

Update*

Ah okay, after changing the replace I get results like this:

Name                                     ManagedBy                                                
----                                     ---------                                                
TestGroup_Modify            testuser=Users,DC=test,DC=domain,DC=com

This is helpful since it starts with the CN, but since every ManagedBy user will have

'=Users,DC=test,DC=domain,DC=com'

appended, would it be possible to filter this string out from results (since all results will have it) to leave just the user CN or would that be outside the scope of powershell? Thanks for your help.

Edit*

Here's what I ran:

$test = 'OU=example,DC=example,DC=test'

$test | ForEach {Get-ADGroup -Filter * -Properties ManagedBy -SearchBase $_} |
Select -Property Name, @{n='ManagedBy';e={$_.ManagedBy -replace '^CN=(.+?),(CN|OU.+)','$1'}} |
Sort -Property Name | 
Format-Table -Property Name, ManagedBy -Force -AutoSize |
Out-File C:\test.csv

Got these results:

Name                                     ManagedBy                                                
----                                     ---------                                                
TestGroup_Modify            testuser=Users,DC=test,DC=domain,DC=com

Just looking for a way to list testuser by itself if possible.

Answer 1

Your replace regex is not correct for what you're trying to do.

I use this one:

$_.ManagedBy -replace '^CN=(.+?),(?:CN|OU).+','$1'

ManagedBy will always be a user DN, so the pattern will be CN=username, followed by either an OU or another CN if it's still in the default Users container.