Version:           unspecified (using KDE 4.7.2) 
OS:                Linux

Back button which used to appear in nested menus to the very left of the menu is absent in 4.7. I consider it's a big usability bug as new way of nagigation (using string at the top right corner) takes enormous time to go back compared to Back button.
I think the button should be returned back.

I attach an edited screenshot. Unfortunately, I have no screenshots of the menu with the button so I painted it by myself (black). The string which took over the button is selected with red. 

Reproducible: Always

Steps to Reproduce:
1. Open Kickoff menu.
2. Go to some of submenus.
3. Notice that there's no Back button at the left side of the menu anymore.

Actual Results:  
To return back you need to find special navigation string, decide what item was you previous one, find it in the string and click it.

Expected Results:  
If there were Back button, you'd need just click it and that's it.