Nested timelines in d3.layout.timeline.
You enable nested support by setting the timeline.children() accessor (which by default returns null) and pass the timeline either an array of time bands with child elements or a hierarchically structured JSON object (as in this example).
Child timeline heights are relative to the top-level parent(s).
Note that with nested timelines maxBandHeight only applies to the top-level parent (in the case of a single root node like this, it is the exact same as the height setting of timeline.size()).
forked from emeeks‘s block: Nested Timelines