This example shows a hierarchical tree of movies organized by release year and country of origin, with each movie as a leaf node. The visualization uses colored shapes—circles for years, rectangles for countries, and ellipses for movies—to represent different levels of the hierarchy. The D3.js v3 library builds the collapsible tree layout, using SVG elements for rendering. The code defines `treeData` as a static JavaScript array, and the legend explains the shape-color mappings for the categorical data.