Character Viewer and Character Palette are NOT the same

For any specific Unicode Character, you can see the fonts that have it in the Font Variation pane at the bottom right of Character Viewer.

For any specific font, you can see all the glyphs it contains in Font Book, View = Repertoire.

Some people find the app Ultra Character Map useful, it has some other options.

Debora Young wrote:

I believe Ultra Character Map will do exactly what I want, and then some. And for $10, will be well worth it. Thanks for the suggestion. I was hoping for something as useful and easy-to-access as Character Palette, but it doesn't look like Apple will be reviving that function.

Let me know if Ultra Character Map is still missing something you need. Glyphs which are not in Unicode (variants, ligatures, etc) may require a different approach.

Actually Character Palette and Character Viewer are essentially the same. You may be thinking of the old version of Keyboard Viewer, which used to have a place where you could select the font, and thus easily see the different characters which different fonts would let you make from the keyboard. Apple dropped the font selector, presumably because almost all fonts provided by Apple now conform to Unicode and will not show any thing different for the code points that the keyboard can reach. There are still some exceptions to this like Bodoni Ornaments, however, where being able to choose the font would be useful.