I've done something similar (though not quite as complicated) a couple of times - and it's not that difficult to do (search-wise, anyway).
I ended up building the dialogs programmatically. That gave me the ability to add what are called "tags" to the dialog window objects. (A better way these days would be to add the string/help text as a linked object itself). Then I just scanned the tags. What I *didn't* do at the time was the elegant display of _just the results_ displayed in their own pane/modal dialog/window. Nowadays I'd probably disable all the non-matching components in that dialog, just as a shortcut.
I agree, there are some really elegant programs out there, also with complex preferences, that now provide this type of search facility. If anyone's ever used Opus, you'll know what I mean. (I'll grab some screenshots when I get it reinstalled) But I wouldn't expect that level of sophistication here, it's probably overkill!
The reason I didn't post this in the wishlist initially was that I considered this more of a 'debugging' request, rather than a feature people would regularly use. But I guess with something as flexible and powerful as MusicBee is becoming, it would be useful to a wider range of folks than I thought... cool!