How to do drilldown d3 topojson map

Question

I have started working on D3 recently.

1. Start with, I want to load country level map with just showing country boundary, states and bubble in the centre of each state, with summarised value.

2. When user click on to specific state, map will smoothly zoom in to specific state and cover full svg and load state map with postal areas and each postal area has its own bubble showing details of that particular locality.

3. When user click on specific postal locality, map will smoothly zoom in specific locality and cover full svg and load locality map with suburbs and each suburb has its own bubble showing details of that particular suburb.

using this code to zoom to bounding box http://bl.ocks.org/mbostock/4699541

I would like to use topojson but I dont mind with geojson.

Any working example like this would be good. or any guidance will be helpful.

Thanks in advance.