Not sure I totally understand, but sounds like you want to use a resource in a slot but have different urls depending the page youre on.
Data variables now act like CSS variables in that if you define --background: blue on the parent then --background: red on the child, the later will override the former.
So in theory I think it should work by defining the more specific url on each page and the resource would depend on that and traverse to the Global root as a fallback url.
Please report back, would love to hear how that goes