This interactive tree diagram visualizes Walmart’s sales hierarchy, breaking down the corporate root into four stores and then into February 2010 weekly sales dates, with holiday weeks marked. Built with D3.js (version 3.5.17), the SVG visualization uses a `d3.layout.tree` to position nodes and animates expanding and collapsing branches through `transition` and click handlers. Node colors are assigned by depth via a `category10` scale, and the data is manually converted from a flat parent-child list into the tree structure.