Abstract: A display area displays a subset of a set of items. Items may be the ancestor or descendant of one or more other items. As an ancestor item having one or more visible descendant items becomes not visible, for example by scrolling outside the display area, a proxy in the display area is automatically created. The proxy corresponds with the ancestor item not visible in the display area. Multiple proxies may be displayed in the display area to present a complete view of the hierarchy containing at least some of the items visible in the display area. Items that do not have descendant items visible in the display area will not generate corresponding proxies when they become not visible. Proxies may be active user interface elements. Conversely, if an ancestor item becomes visible in the display area, any corresponding proxies are automatically removed.