Hey John - Sorry if those instructions weren’t too clear. To further clarify, if someone lands on your landing page with URL parameters then those existing parameters can be automatically appended to outgoing button links.
For example, if your landing page url is www.mylandingpage.com and someone comes on to the landing page with the following parameters:
Then ?affiliate_id=5555&source=facebook will automatically be appended to any button with the “Pass through URL parameters” box checked.
Does that make sense? Was that what you’re looking for? If not clarify a bit further as to what you’re trying to do and i’d step you through the best I can