Command user interface for displaying multiple sections of software functionality controls

To increase command-access efficiency and to optimize a user's available user interface work space, an improved user interface is provided for displaying logical groupings of selectable software functionality controls that are associated with one or more selected top-level functionalities. Upon selection of a top-level functionality tab, selectable functionalities associated with the top-level functionality tab are divided into logical groupings and are presented in a customizable functionality control section below the tab. Upon selection of a different top-level functionality tab, selectable functionalities associated with the subsequently selected top-level functionality tab may either replace the first functionality control section or may be displayed in a separate functionality control section adjacent to the first functionality control section if real estate is available in the user interface.