Fetch details of the groups accessing document library in SharePoint - powershell

Question

I am trying to access the group information (group name and its members) who can access a Document Library in a SharePoint website.
Allow me to explain using an example:
For a site named "MyCompany" there are sub-sites as Finance, HR,etc. Each sub-site has a document library named "Shared Document", and in each Shared document has folders and sub-folders.
The access to these Shared Document is given to different groups like HR Managers are given access to Shared Document in HR sub-site.
I want to fetch the data of the groups that can access these Shared Documents as shown below:
Site : MyCompany (URL/Title)
Sub-site : HR (URL/Title)
Folder : Shared Document (Name/URL)
Group : HR Managers
Member : John
I am able to fetch group information up to sub-site level. But enable to do so at document library and sub-folder level.
My script so far:
Add-PSSnapin Microsoft.Sharepoint.Powershell
Start-SPAssignment -Global
$sysdate = Get-Date -UFormat "%m_%d_%y"
$sites = get-spsite http://MyCompany_Url
$sites
foreach($site in $sites)
{
[array]$users = $null
#$name = $site.RootWeb.Title
write-host -foregroundcolor green "Working on Site Collection: "$site.RootWeb.Title "..."
foreach ($web in $site.AllWebs)
{
write-host "--Working on web:" $web.Title "..." -foregroundcolor yellow
$webTitle = $web.Title
foreach($l in $web.Lists)
{
#Check for only document libraries
if($l.BaseType -eq "DocumentLibrary")
{
if($l.Title -eq "Shared Documents")
{
Write-Host $l.Title"(Web: "$web.Title")" -ForegroundColor DarkRed -BackgroundColor White
$grpinfo = $l.RoleAssignments
$groupinfo
<#foreach($item in $l.Items)
{
$ItemUrl = $item.Url
$ItemTitle = $item.Title
Write-Host $item.Url" : "$item.Title -ForegroundColor green
}#>
}
}
}
# # Getting group ifo at sub-site level
foreach ($group in $web.groups)
{
write-host "----Collecting users from group:"$group.Name "..." -ForegroundColor Magenta
#$GrpPermission = $roles.Type + ":"+ $roles.Name
foreach($user in $group.users)
{
$usrname = $user.DisplayName
$UserPerm = $user.Roles
$GroupPerm = $group.Roles
[string]$UPerm = #($UserPerm.Name) -join ","
[string]$GPerm = #($GroupPerm.Name) -join "," #-replace (" ", ",")
Write-Host "################"
$GPerm
Write-Host "----------------"
$UPerm
Write-Host "################"
write-host "-----"$user.DisplayName" : "$group.name" : "$web.Title" : "$site.RootWeb.Title " Group Permission : "$group.Roles " Member Permission : "$user.Roles -ForegroundColor Blue -BackgroundColor White
$users = new-object psobject
$users | Add-Member NoteProperty -name "Webpart Name" -value $web.Title
$users | add-member noteproperty -name "Groups" -value $group.name
$users | add-member noteproperty -name "Display Name" -value $user.DisplayName
$users | add-member noteproperty -name "Group Permission(s)" -value $GPerm
$users | add-member noteproperty -name "Webpart URL" -value $web.Url
#$users
$users | export-csv -path "E:\MyCompany_Groups_report_$sysdate.xls" -Append -NoTypeInformation
}
}
$web.Dispose()
}
$site.Dispose()
}
Stop-SPAssignment -Global