foreach (var collectorItem in new FilteredElementCollector(document).OfClass(typeof(RevitLinkInstance)))
{
if (collectorItem is RevitLinkInstance revitLinkInstance)
{
Transform transform = revitLinkInstance.GetTotalTransform();
....
XYZ pnt = positionPoint.Point;
if (null != transform)
{
pnt = transform.OfPoint(pnt);
}
}
}