This example shows a two-level force-directed graph with outer nodes (A, B, C) connected in a triangular layout, each containing two inner child nodes linked by additional edges. Using D3.js v6, the visualization employs two separate `d3.forceSimulation` instances—one for the larger outer network and another for the inner child connections—both rendered as SVG circles and lines. Pink outer nodes and orange inner nodes are draggable via D3’s drag behavior, with positions updated on each tick event. The code defines static graph data inline and positions elements across the full browser viewport.