Scroll Panel inside another Scroll Panel?

Me again.

Come across a slight annoyance. Not able to add a second scroll panel inside another. 

As I continue creating software sims, another niggle I am struggling to replicate is where you select a link on the 'web page' already within a scrolling panel. This opens a pop up where the user selects from options. But these options are scrolling within the pop up. And if the user 'scrolled' down the main web page the pop up would also scroll up.

Web Page Gif attached

So my issue is that you can not add a second scroll panel inside another to replicate this, so the 'pop up' image with a scrolling panel on it stays fixed.

SL Page Gif attached

I have seen other posts on this, but this are a few years old now with little help. So am hoping as we jump to present day this is something where there is a workaround....possibly.