This example displays time-series medical data for a single patient, filtering the dataset to show only the selected metric (Diastolic pressure) across time. The visualization uses nested line charts and area fills, with each line representing a data category and color-coded via `scaleOrdinal` and `schemeSet1`. The chart is built with D3 v5, using `nest()` to group data, SVG rendering for paths, and includes interactive tooltips and a listening rectangle for mouse events. Data is loaded from a CSV file containing patient measurements.