<button onclick="getSelectedFiles()" class="k-button">Get selected files</button>
<div id="fileManager"></div>

<script>
  var baseUrl = "https://demos.telerik.com/service/v2/core/filemanager/";

  $("#fileManager").kendoFileManager({
    width: 500,
    dataSource: {
      transport: {
        read: {
          method: "POST",
          url: baseUrl + "Read"
        }
      }
    }
  });

  function getSelectedFiles(){
    var filemanager = $("#fileManager").getKendoFileManager();
    var files = filemanager.getSelected()
    /* The result can be observed in the DevTools(F12) console of the browser. */
    console.log(files)
  }
</script>