Displaying sub-data rows inside a row in SlickGrid Table

I've started using SlickGrid and have to implement a kind of functionality where I need to show sub-row inside a parent row of SlickGrid.

Here's the scenario

Here's Asia, Europe is having sub categories in Services Column and these service columns are expandable/collapsible

I'm trying to customize this for first column.

Is any other link/source available to refer to accomplish the feature.