Most definitely not the one he's talking about. But, I'll mention my extension. It exposes the hidden date operators through Youtube's search filter menu, allows searching comments and finding the most popular video's from a channel within the last year, etc.

https://github.com/polywock/youtubeEye

You could probably vibe-code it if it doesn't exist. You're literally just adding extra parameters to the search request. Hard part is creating the interface for it. Saw more options looking for Firefox extensions than Chrome for this, though that might be expected.