Xpages, Sessionscope & XML

I’m new to 8.5, I am trying to better understand how sessionscope works. From what I have read I should be able to use it to save url so I can use it as a data source to populate the fields on my xpage.

So my question is how to do I tell xpages to recognize the link as the data source and then use that data to populate a name and email field?

so far I have a button that is able to save the url into the sessionscope, just not sure what to do after that. Any advice would be appreciated.

Subject: simple thing

open another xpage with computedfield with value sessionscope.someurl