This is an adaption of a Zoomable sunburst example with an added text box showing which item was last clicked.
Click on any arc to zoom in. Click on the center circle to zoom out.
A sunburst is similar to a treemap, except it uses a radial layout. The root node of the tree is at the center, with leaves on the circumference. The area (or angle, depending on implementation) of each arc corresponds to its value. Sunburst design by John Stasko. Data courtesy Jeff Heer.