Load second route/view (not nested) into modal

Hi All,

after digging around for a while now without getting answers, I would like to ask you for your knowledge.
I have the case (by customer) that I need to load into a modal a complete other view than the one I am currently on. So staying on a specific route and load into a modal another route which is not a nested route. I saw quite a lot examples for displaying nested routes into a modal. But in my case the routes should not be nested and I also should not leave the route where I am currently on when displaying the other route in the modal. Does anybody out there has an idea how to achieve this? Cause I am for a while now quite desperate. Thanks in advance.