Oh, sorry, I misunderstood.

The way it works is that when you bind an object as the DataSource of the grid, the grid checks to see if the object implements IList or IBindingLIst. The items in the list become rows and the properties on those items become columns. If one of the properties returns an IList or an IBindingList, then that property is treated as a child band.

There's no automatic way to break down a single property into multiple child properties. But you could achieve this in any number of ways.

• You could hide the "real" columns and add unbound columns to the grid for each property you want to display. You would use events of the grid to populate the unbound columns with data from the "real" columns - probably in the grid's InitializeLayout event. If the fields are updatable, then you will need to copy the edited values back into the real object columns - probably in BeforeRowUpdate or maybe AfterCellUpdate.
• You could do essentially the same thing by exposing properties on your data objects. Perhaps the two sub-object properties should be internal to the class and then the class can expose the individual child properties as it's own.
• You could Implement ITypedList on your main object and create your own custom PropertyDescriptors that translate the child properties into sort've virtual properties on the object itself.

That doesn't really answer the question I have a class which exposes 2 other classes as properties.  When I bind to the grid it shows those class properties as 2 columns.

How do I specify the columns I want to appear from the properties of the 2 classes I have in the class I am binding to?