How to import xml file and get the current family's parameter through dynamo?

Recently,I got a video about how to creat tunnel through dynamo.It’s a great job!But the video show the process through dynamo player,I can not see the script.I only saw the author constantly modify the current family parameter in the family type and then run the dynamo player.So I guess the script maybe contain some nodes that can get the current family parameter.Who can tell me how to do that?Thanks a lot!

Hi @Margin