public bool CanHighlight {get;}

var tv = TableView.Active;
if (tv == null)
  return;

QueuedTask.Run(() =>
{
  // get list of current selected objectIDs
  var selectedObjectIds = tv.GetSelectedObjectIds();
  var idsToHighlight = new List<long>();

  // add the first two selected objectIds to highlight
  if (selectedObjectIds.Count >= 2)
  {
    idsToHighlight.Add(selectedObjectIds[0]);
    idsToHighlight.Add(selectedObjectIds[1]);
  }

  // highlight
  if (tv.CanHighlight)
    tv.Highlight(idsToHighlight, true);
});