Each node on the tree is labeled with a record ID. When one is selected it changes colors and the data within the record is shown on the rightside panel. Note the alternate coloring of the panel text that is intended to distinguish between different items in a compact sequence of entries, and the tooltip that drops down whenever the mouse pointer is hovered over the purple demographic bullet point. The tooltip is a means to present sorted detail info concerning the bullet point while minimizing screen clutter.
The lower screenshot shows the page again with the configuration panel dropped down to reveal the list of record fields that can be shown or hidden in the right side panel.