Export Folder Permissions - powershell

Question

I want to Export folder Permissions for a subset of folders.
Each Folder in Department has two child's, Public and Internal.
For example, I want the permissions of the folder D:\Data\Department\Science\Public or D:\Data\Department\Sales\Public.
$FolderPath = dir -Directory -Path "D:\Data\Department" -Force
$Report = #()
Foreach ($Folder in $FolderPath)
{
$Folder2 = Join-Path -Path $Folder -ChildPath "Public"
$Acl = Get-Acl $Folder2.FullName
foreach ($Access in $acl.Access)
{
$Properties = [ordered]#{'FolderName'=$Folder2.FullName;'AD
Group or User'=$Access.IdentityReference;'Permissions'=$Access.FileSystemRights;'Inherited'=$Access.IsInherited}
$Report += New-Object -TypeName PSObject -Property $Properties
}
}
$Report | Export-Csv -path "C:\Users\adminrw\FolderPermissions.csv"
Error:
Get-Acl : Cannot validate argument on parameter 'Path'. The argument is null or empty. Provide an argument that is not null or empty, and then try the command again.
At line:7 char:16
+ $Acl = Get-Acl $Folder2.FullName
+ ~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Get-Acl], ParameterBindingValidationException

Answer 1

It looks like the Join-Path in your script is taking the Name of the folder and adding the childpath to it. This results in $Folder2 ending up like SomeFolder\Public
Try using
$Folder2 = Join-Path -Path $Folder.FullName -ChildPath "Public"
This will make $Folder2 : D:\Data\Department\SomeFolder\Public

Answer 2

I've corrected script. Please use below code:
$FolderPath = dir -Directory -Path "D:\Data\Department" -Force | Select *
$Report = #()
Foreach ($Folder in $FolderPath)
{
$Folder2 = Join-Path -Path $Folder.FullName -ChildPath "Public"
$Acl = Get-Acl $Folder2
foreach ($Access in $acl.Access)
{
$Properties = [ordered]#{'FolderName'=$Folder2.FullName;'AD
Group or User'=$Access.IdentityReference;'Permissions'=$Access.FileSystemRights;'Inherited'=$Access.IsInherited}
$Report += New-Object -TypeName PSObject -Property $Properties
}
}
$Report | Export-Csv -path "C:\Users\adminrw\FolderPermissions.csv"