To show off a complex hierarchical tree of options within their software applications, Giva Labs developed a jQuery based slick hierarchical combo box, called “mcDropdown”. Some of the features of mcDropdown include:

• Creates a multi-column hierarchical select UI component
• Binds a text input field or div element to a list element (included nested lists)
• Menus are automatically split into columns as needed
• Menus are positioned to always stay on the screen
• Autocomplete keyboard entry (only valid options are allowed)
• Menu automatically scrolls into viewport when opened

More info: mcDropdwon

Source:→ Ajaxian