Group Headings Datagrid Form

[nlexa]

Say I had the following comma delimited list of information:

Residential,Ashburton,1,2,0,1
Residential,Brighton,2,0,0,0
Residential,Cashmere,3,1,2,1
Residential,Dallington,5,0,0,1
Rural,Clyde,1,0,0,0
Rural,Rangiora,5,2,0,0
Rural,Sefton,4,3,2,1
Industrial,Opawa,2,0,0,0
Industrial,Sydenham,0,1,0,0

I would like to display this in a datagrid form like so:

Residential +

Rural -

Clyde
1 bedroom

Rangiora
5 bedrooms
2 bathrooms

Sefton
4 bedrooms
3 bathrooms
2 garage
1 pool

Industrial+

Each group of records has its own heading (Residential, Rural and Industrial) which can expand (with a plus and minus) to show the individual records under the heading.

I have seen some images of examples that look like this http://lessons.runrev.com/s/lessons/m/d ... -Examples- particularly image 2 and 5.
I have checked the tutorial on how to expand and contract identical records http://lessons.runrev.com/s/lessons/m/d ... -Contract-
So I can make each record expand and contract. But how do I get a headings like in image 5?