Hi

My code MultiGrouping Grid and Summary ( ExtJs 4.0.7 or higher )

MultiGrouping
Снимок экрана 2012-09-15.jpg
MultiGroupingSummary
Снимок экрана 2012-09-15.jpg

mg.zip

Store:
...
groupers: ['field1', 'field2', 'field3', ...]

Grid:
features: [{ ftype: 'multigroupingsummarymy' }]
or
features: [{ ftype: 'multigrouping' }]

P.S. rebuild - http://www.sencha.com/forum/showthread.php?226739-MultiGrouping-and-MultiGroupingSummary
Thank you - ExTriqui