How to show certain widget (pages AND SUBPAGES) only in certain “pages”

This is tricky: I’m trying to use the “pages widget” as “contestual menus” in the sidebar for the various sections of my site. This means I need to display a different “pages widget” for every “main page” and their relative subpages. I tried different plugins, but none of them allow me to do so (the one that comes closer to my needs is “Widgets “Context” with the “target by url” option, but no subpages).
Can anyone help please?