Oooo, fun question. So Strapi doesn’t populate fields/relations when certain field values are selected.
However, you could customize/extend the admin panel to make it do what you need – maybe in combination with a custom plugin. Admin panel customization | Strapi Documentation and Developing plugins | Strapi Documentation
After looking into it some more it does look like there’s an open ticket for this kind of functionality: Parent & child relationship/field | Content Editing XP | Strapi
It also looks like dimatkach11 (DIMA here in this discord) has made a custom plugin for this exact functionality here: GitHub - dimatkach11/strapi_plugins