The left sidebar provides me access to all of my work: the content I have access to, my personal messages and settings as well as Magnolia configuration settings and tools.
These three areas have separate menus, each offering menu and sub menu items for accessing various data sets and functions. Only one of these menus is visible at once. I can however switch freely between areas and menu items without loosing context. If I e.g. work on assets, then switch to my personal work area to moderate a number of new forum entries, then switch back to the asset browser again, I'm returned to the exact same point where I left of.