javascript - Zoom to region on Zoomable Treemap Bar Chart -

i've implemented nice zoomable treemap bar chart chris given, i'm having trouble making behave bit different. i'd first zoom regions , rebuild chart, allowing 1 click further each country.

i've tried modifying code below in order give layer

var continents = types.selectall('.continent')         // note we're using our copied branch.         .data(function (d) { return d.treemaproot.children },               function (d) { return d.data.continent })  var entercontinents = continents.enter().append('g')         .attr('class', 'continent')         .attr('x', function (d) { return d.value ? d.x0 : x1.bandwidth() / 2 })         .attr('width', function (d) { return d.value ? d.x1 - d.x0 : 0 })         .attr('y', 0)         .attr('height', 0)         .style('fill', function (d) { return color(d.parent.data.continent) }) 

but i'm having difficulties getting run. breaks countries within continents.

thank you.