If you go to a folder/place which has several folders inside so that you have to scroll down to see the very last folder. Now open that very last or the second last folder, now press back button. Here you will notice that finder will take you on the top of the page instead of keeping the focus to the last line of folders which you came out from. I have tested this is on Yosemite. I can confirm that in previous versions of OS, it wasn't the case! if you go inside a folder and come out by pressing back, the focus of Finder stays there on same folder area which you came out from. Now in El Capitan, when you press back button, it scrolls to the top of the page and you have again scroll down to see those folders. This is a really annoying bug which I have been sending reports since beta 1 and Apple has not fixed this until this date.