Overwatch – What Do the 4 Blue Bars Underneath the Crosshair Mean for Doomfist?

From your comments that you may have switched heroes during your games, it appears to be a percentage of each game played * 1 per each win. So if you won four games where you played D.Va for 75% of each of the games and Mei for 25%, you would have the D.Va bar show 4*0.75 = 3 wins and Mei would show 4*0.25 = 1 win.

These bars obviously wouldn't show up as whole numbers most of the time if you switch heroes often during games as it is unlikely that you would end up with exact amounts of whole games played. It seems to round numbers to the nearest whole, so each of those games that you won that you played the character for less than 50% of the time slightly fills up the bar but is labelled as "0 wins."

Anything you get you on the PTR server, Levels and drops, stays on the PTR Server. So yes they are specific and do not transfer over to the "proper" Overwatch servers.

The FAQ on the overwatch page gives the answer Source

Q. Will any progress I make on the PTR transfer over to the live game?

A. No. Any progression earned during the PTR—including levels, achievements, stats, skill ratings, loot boxes (including rewards from loot boxes), currency (including Competive Points), and cosmetic items unlocked with currency—will not transfer over to the live game.