Hi Dave,
We don't have plans to add that level of detail to CrUX, and in many cases it would likely only be a partially complete story as many paths would fail to meet the minimum privacy thresholds for many paths. We would suggest using a RUM solution to allow that level of granularity. CrUX, as a public dataset, is more intended as a high-level indication of performance than a fully queryable, segmentable solution such as that that can be offered by RUM.
The nearest thing that is available now is the Page Grouping in Google Search Console, but I know that is not quite in the same level of detail as you're asking for (perhaps for the same reasons as above?), and is only available to verified owners of that domain (again, perhaps for that reason). As that's managed by the separate Search team we in the CrUX team don't have any more visibility into that.
Thanks,
Barry