Assuming multiple familes have not been loaded into project.
I find in this thread, DANEdu, people use DANEdu to add parameter to one family at once.
But I have lots of families. If I do like as below, I use Orchid “Document.BackgroundOpen” and “Parameter.Add”,
I prefer to use native node “FamilyDocument.AddParameter”, but I can’t find a native node to convert output from “FileSystem.GetDirectoryContent” to family document.