public KnowledgeGraphInvestigation Investigation {get;}

{
  // access the currently active knowledge graph investigation view
  KnowledgeGraphInvestigationView activeView = KnowledgeGraphInvestigationView.Active;
  KnowledgeGraphInvestigation investigation = activeView?.Investigation;
  if (investigation != null)
  {
    // perform some action
  }
}

{
  // get the active investigation view
  var iv = KnowledgeGraphInvestigationView.Active;

  await QueuedTask.Run(() =>
  {
    // get the investigation
    var inv = iv.Investigation;

    // get the set of selected records
    var idSet = iv.GetSelectedRecords();

    // view these records in a link chart
    var map = MapFactory.Instance.CreateLinkChart("myLinkChart", new Uri(inv.ServiceUri), idSet);
    ProApp.Panes.CreateMapPaneAsync(map);
  });
}