Get-BGPCommunities.ps1

<#
Written with version 3.5.0 of the Azure PowerShell Module 
available from here https://github.com/Azure/azure-powershell/releases/tag/v2.8.0-October2019
Install-Module -Name Az -Repository PSGallery -RequiredVersion 3.5.0 -Force -AllowClobber
Migration instructions Azure.RM to Az - https://azure.microsoft.com/en-au/blog/how-to-migrate-from-azurerm-to-az-in-azure-powershell/
#>

Login-AzAccount | Out-Null

$subscriptions = Get-AzSubscription
$cnt = 1
Write-Host "ID    Subscription Name"
Write-Host "-----------------------"

foreach ($sub in $subscriptions){
    Write-Host "$cnt   $($sub.name)"
    $cnt++
}
$selection = Read-Host -Prompt "Select a subscription to deploy to"
$subSelect = $subscriptions[$selection - 1] # Revert 1-index to 0-index

Select-AzSubscription $subSelect.SubscriptionId

#############################################################################

$CommunityNames = (Get-AzBgpServiceCommunity).BgpCommunities.CommunityName
$cnt = 1
foreach ($CommunityName in $CommunityNames){
    Write-Host "$cnt   $CommunityName"
    $cnt++
}

$selection = Read-Host -Prompt "Select a Community Name to get the BGP communities"
$CommunityNameSelect = $CommunityNames[$selection - 1] # Revert 1-index to 0-index

Get-AzBgpServiceCommunity | ? {$_.BgpCommunities.CommunityName -eq $CommunityNameSelect}