The script below demonstrates how you can list VMs cloned from snapshots. It checks each VM to see if it has a parent snapshot by examining its disk’s parent disk. If the parent disk is a snapshot, it implies the VM was cloned from that snapshot.

# Connect to vCenter Server
$vcServer = 'your-vcenter-server'
Connect-VIServer -Server $vcServer -Credential (Get-Credential)

# Function to check if a VM is cloned from a snapshot
function Check-VMClonedFromSnapshot {
    param (
        [VMware.VimAutomation.ViCore.Impl.V1.Inventory.VirtualMachineImpl]$VM
    )
    
    $isClonedFromSnapshot = $false
    $vmDisks = Get-HardDisk -VM $VM

    foreach ($disk in $vmDisks) {
        $diskInfo = $disk.ExtensionData.Backing
        if ($diskInfo.Parent -ne $null) {
            $parentDisk = Get-View -Id $diskInfo.Parent.VmSnapshot
            if ($parentDisk -ne $null) {
                $isClonedFromSnapshot = $true
                break
            }
        }
    }

    return $isClonedFromSnapshot
}

# Get all VMs
$vms = Get-VM

# Check each VM and report if it is cloned from a snapshot
foreach ($vm in $vms) {
    if (Check-VMClonedFromSnapshot -VM $vm) {
        Write-Host "$($vm.Name) is cloned from a snapshot."
    }
}

# Disconnect from vCenter Server
Disconnect-VIServer -Server $vcServer -Confirm:$false