Show selected category records

Hi Guys, 

I've got the following that produces 2 navigational block.  Main and Section.  The Main Nav is showing the top level items, the Section Nav is showing the 2nd level.  But how do I change it to show only the 2nd level from the selected main level?

  // load detail record
  list($pagesRecords, $pagesMetaData) = getRecords(array(
    'tableName'   => 'pages',
    'where'       => whereRecordNumberInUrl(1), // If no record # is specified then latest record is shown
    'loadUploads' => true,
    'allowSearch' => false,
    'limit'       => '1',
  ));
  $detailRecord = @$pagesRecords[0]; // get first record
  if (!$detailRecord) { dieWith404("Record not found!"); } // show error message if no record found

  // load records for 'MAIN NAVIGATION'
  list($level1Records, $level1MetaData) = getRecords(array(
    'tableName'   => 'pages',
    'loadUploads' => true,
    'allowSearch' => false,
    'where'       => "depth = 0"
  ));

  // load records for 'SECTION NAVIGATION'
  list($pagesRecords, $pagesMetaData) = getRecords(array(
    'tableName'   => 'pages',
    'orderBy'     => '',   // use default database order
    'loadUploads' => false,
    'allowSearch' => false,
    'where'       => "depth = 1"
  ));