Major migration at the department level..
Thanks to [git-ashish’s block] (http://bl.ocks.org/git-ashish/8959771), I could moke this fast enough to allow for exploration…
And as always, Mike Bostocks’ examples have been a huge resource.
Click on any node to filter from that node’s perspective. Click on the white chart background (not a node or a link) to go back up all departments.