A treemap visualization system can include a treemap configured to visualize a set of nodes. The treemap visualization system also can include an event handler programmed to process a proximity event associated with a specific portion of the treemap. The event handler can process the proximity event by visually coupling selected nodes which are inter-related to a node associated with the proximity event. The system further can include logic for displaying a direction for each inter-relationship between the selected nodes and the node associated with the proximity event. In this regard, the proximity event can include a mouse-over event, a mouse-click event, and a keyboard selection event.