The implementation of the invention involves a conventional display window and a system for displaying a portion of said hierarchical tree within the borders of the window in combination with an implementation enabling a user to expand each nested displayed category into a displayed list of items in said category, and to collapse said displayed list back to each displayed category. There are means for scrolling said displayed hierarchy through said window. This invention provides for a set of displayed indicators, each representing a hidden expanded category in the hierarchical chain of a list of items displayed within said window. There is a further implementation associated with each displayed indicator enabling a user to select the indicator to collapse the hidden category represented by said indicator and thereby enable the display of the collapsed category within said window.