You can have the Windows taskbar or system tray visible while in Unity view.

Show the taskbar by selecting View > Show Taskbar in Unity.

You might have to move the location of the Mac Dock to see the taskbar.

The Hide System Tray menu item is dimmed.

Hide the taskbar by selecting View > Hide Taskbar in Unity.

Show the system tray by selecting View > Show System Tray in Unity.

Hide the system tray by selecting View > Hide System Tray in Unity

When they are set to show, these elements also remain visible when you switch to work in non-Windows applications.