Four push buttons switch between quarters in a health dataset for traumatic brain injuries, updating a bubble chart and bar chart side by side. The bubble chart uses `d3.pack` and `d3.hierarchy` to size circles by visit counts for anxiety, neurology, sleep, and headache, while the bars show total TBI visits and symptoms. Buttons call an `update` function that re-binds data and transitions the SVG elements, demonstrating an interactive alternative to a time-series axis.