Powershell Get values from nested arrays for Textboxes - arrays

Question

I'm trying to create a gui with comboboxes and textboxes. If the user select a item from the Combobox, the related values from an array should appears in textboxes. Can someone give me a clue? I already tried to enumerat thru the arrays and select the key/value pair with -eq, but unfortunately I was not able to solve it this way.
Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()
#Arrays
$CB_NDL_Array = #{
City1 = #{
Street = "Test1"
Postalcode = "5435"
}
City2 = #{
Street="Test2"
Postalcode="23423"
}
City3 = #{
Street="Test3"
Postalcode="234"
}}
$UserManager.controls.AddRange(#($Vorname,$Nachname,$TB_Givenname,$TB_Surname,$Anmeldename,$TB_SamAccountName,$Passwort,$TB_Password,$Niederlassung,$CB_NDL,$Street,$TB_Streetaddress,$City,$TB_City,$PLZ,$TB_Postalcode,$Buero,$TB_Office,$Abteilung,$TB_Department,$Position,$CB_Title,$Firma,$CB_Company,$Manager,$TB_Manager,$Telefon,$TB_OfficePhone,$Mobile,$TB_Mobile,$UserInfo,$Exchange,$RB_exc_yes,$RB_exc_no,$Email_address,$TB_email_address,$CB_Database,$Database,$B_Create))
$CB_NDL = New-Object system.Windows.Forms.ComboBox
$CB_NDL.text = ""
$CB_NDL.width = 100
$CB_NDL.height = 20
$CB_NDL.location = New-Object System.Drawing.Point(110,180)
$CB_NDL.Font = 'Microsoft Sans Serif,10'
$CB_NDL.SelectedItem
$Street = New-Object system.Windows.Forms.Label
$Street.text = "Strasse"
$Street.AutoSize = $true
$Street.width = 25
$Street.height = 10
$Street.location = New-Object System.Drawing.Point(15,210)
$Street.Font = 'Microsoft Sans Serif,10'
$TB_Streetaddress = New-Object system.Windows.Forms.TextBox
$TB_Streetaddress.multiline = $false
$TB_Streetaddress.width = 100
$TB_Streetaddress.height = 20
$TB_Streetaddress.location = New-Object System.Drawing.Point(110,210)
$TB_Streetaddress.Font = 'Microsoft Sans Serif,10'
$City = New-Object system.Windows.Forms.Label
$City.text = "Ort"
$City.AutoSize = $true
$City.width = 25
$City.height = 10
$City.location = New-Object System.Drawing.Point(15,240)
$City.Font = 'Microsoft Sans Serif,10'
$TB_City = New-Object system.Windows.Forms.TextBox
$TB_City.multiline = $false
$TB_City.width = 100
$TB_City.height = 20
$TB_City.location = New-Object System.Drawing.Point(110,240)
$TB_City.Font = 'Microsoft Sans Serif,10'
$PLZ = New-Object system.Windows.Forms.Label
$PLZ.text = "PLZ"
$PLZ.AutoSize = $true
$PLZ.width = 25
$PLZ.height = 10
$PLZ.location = New-Object System.Drawing.Point(15,270)
$PLZ.Font = 'Microsoft Sans Serif,10'
$TB_Postalcode = New-Object system.Windows.Forms.TextBox
$TB_Postalcode.multiline = $false
$TB_Postalcode.width = 100
$TB_Postalcode.height = 20
$TB_Postalcode.location = New-Object System.Drawing.Point(110,270)
$TB_Postalcode.Font = 'Microsoft Sans Serif,10'
$CB_NDL.Add_SelectedIndexChanged({
$TB_City.text = $CB_NDL.SelectedItem
$TB_Postalcode.text = $CB_NDL_Array.values | Where-Object{$CB_NDL.SelectedItem} | Where CB_NDL_Array.$_.key -eq "Postalcode" })
foreach ($NDL in $CB_NDL_Array.keys){
$CB_NDL.items.AddRange("$NDL")
}
foreach ($Title in $CB_Title_Array){
$CB_Title.items.add("$Title")
}
foreach ($Company in $CB_Company_Array){
$CB_Company.items.add("$Company")
}
[void]$UserManager.ShowDialog()

Answer 1

$SelectedItem=$CB_NDL.SelectedItem
$TB_Postalcode.text = $CB_NDL_Array.$SelectedItem.Postalcode