Great timing to bring this up @hcchen !
There are a couple approaches we support today that might be a good fit (or might not, depending on some details).
We're also in the early stages of a feature that's more narrowly designed to show the nearest neighbors in vector space. Are you open to a call? I'd love to talk through your use case to figure out
1) How we can help today, and
2) What we can do in the nearest neighbors feature we develop to potentially make it a better fit for your use case when it's ready?
If you are open to chat, drop me a line at firstname.lastname@example.org and we can schedule it.
VP, Decision Intelligence at DataRobot