so70436847.php

<?php
  function getSourceData() {
    $iterator = [ 
      ["one"=> 1, "two" => 2, "thre" => 3],
      ["one"=> 11, "two" => 12, "thre" => 13]
    ];
    $itemSelector = "content/image/filePath"; 
    foreach ($iterator as $row) {
      $source_data[] = $row;
    }

    $selectors = explode('/', trim($itemSelector, '/'));
    foreach ($selectors as $selector) {
      echo $selector;
      if (!empty($selector)) {
        var_dump($source_data);
        $source_data = $source_data[$selector];
        var_dump($source_data);
      }
    }
    return new \ArrayIterator($source_data);
  }

  var_dump(getSourceData());