Chess Percentile?

If I’m 92% percentile does that mean I’m 8% best in the world?

you can be better !

On chess.com, yes

Keep in mind that it literally means everyone on the site, and it's not a true apples to apples comparison.  This includes people that barely understand the rules, people that can't stop the Scholar's mate, people that have never heard of Scholar's Mate (let alone en passant), not to mention the millions of accounts that are long inactive after playing one game and quitting.

More useful would be a comparison among active members, at least to weed out the inactive accounts that will never return.  Even better would be a comparison of 'serious' players, people who regularly study books, review games and attend tournaments.  Compared to the entire world, being 1500 is the top 90% of chess ability.  Among serious chess players, though, it is much lower.  

Keep in mind that if you can solve a crossword or a medium Sudoku, you are are in the top 85% of the world for those activities ... because most of the world doesn't do these things.