function ImportTermSet([Microsoft.SharePoint.Taxonomy.TermStore]$store, [string]$groupName, [PSCustomObject]$termSet) {  
  function ImportTerm([Microsoft.SharePoint.Taxonomy.Group]$group, 
                      [Microsoft.SharePoint.Taxonomy.TermSet]$set, 
                      [Microsoft.SharePoint.Taxonomy.Term]$parent, 
                      [string[]]$path) {        
    if ($path.Length -eq 0) {
      return
    } elseif ($group -eq $null) {
      $group = $store.Groups | where { $_.Name -eq $path[0] }
      if ($group -eq $null) {
        $group = $store.CreateGroup($path[0])
      }
    } elseif ($set -eq $null) {
      $set = $group.TermSets | where { $_.Name -eq $path[0] }
      if ($set -eq $null) {
  Write-Host "Create $path[0]"
        $set = $group.CreateTermSet($path[0])
Write-Host "Created $path[0]" 
      }
    } else {
      $node = if ($parent -eq $null) { $set } else { $parent }
      $parent = $node.Terms | where { $_.Name -eq $path[0].Split(";")[1] }
      if ($parent -eq $null) {
        $path[0].Split(";")[0]
        $parent = $node.CreateTerm($path[0].Split(";")[0], 1031)
        ($parent.Labels | ? {$_.Language -eq 1033}).Value = $path[0].Split(";")[1]
        $path[0].Split(";")[1]
        "################"
      } 
    }
    ImportTerm $group $set $parent $path[1..($path.Length)]
  }
  $termSetName = $termSet[0]."Term Set Name"    
  $termSet | where { $_."Level 1 Term" -ne "" } | foreach {
    $path = @($groupName, $termSetName) + @(for ($i = 1; $i -le 7; $i++) { 
      $term = $_."Level $i Term" + ";" + $_."Level $($i + 7) Term"
        if ($term -eq ";") {
          break
        } else {
          $term
        }
      }
    )
    ImportTerm -path $path
  }
}

$url = "http://yoururl:[port]/"
$session = Get-SPTaxonomySession -Site $url
$store = $session.TermStores["Managed Metadata Service Application"]   
$termSet = Import-Csv "C:\temp\TESTFILE.csv" -Encoding Unicode
ImportTermSet $store "mystore" $termSet
$store.CommitAll()