How to pass only the last name value to another name field?

2.  Still looking for some coding help with the last name.  Can't figure out the correct code to have the last name only copy to all the other names on the form.  Just trying to save families time by not having to enter in the same last name multiple times.  I tried to follow a few articles on your forums but couldn't figure it out.  If you could help with this that would be appreciated.

Unfortunately, this is also not possible. You can only pass the first and last name from one Full Name field to another Full Name field. 

The only possible solution is to use Short Text Entry fields for the First and Last name. This would allow you to pass the last name to another last name (Short Text Entry) form field. 

How to Pass Field Value to Another Field?

Here is a demo form - https://form.jotform.com/201691499450057