You may just need a new visualization that shows a comparison of multiple products on a single chart assuming you are comparing during the same time period.
And/or multiple time periods for a product.
For example we do several trend lines where it has year over year comparisons (with month and year as dimensions) showing you a total by month compared to prior year(s).
I believe that, by default, Qlik uses the same session, which is the selections are shared across sheets. When using mashups you can specify a different identity, but I'm not sure how this would be done in native Qlik Sense. As such, this sounds like a job for alternate states, where you would duplicate the existing sheet and then set alternate states for the new charts. In native Qlik Sense (unlike QlikView), alternate states are not included, but there is an extension that you could use. Here's the link: