Property grid question

I have a question:

I use a propery grid for modifyng my objects.
Now I have object A. Object A has an int x and an object b.
object A has also a get/set for x (property X) and a Get/Set for b (property B)

Now i put object A into the property grid. I see the Get/Set property of A in the property grid
but it seems that the propery B has been disabled. How come? Because i need acces to the properties of object b.

How can I realise this ?

the property grid has to be aware of how to design your property. native types (int, bool, enums, strings, ...) have designers and type editors already built for them.

Here's an article that kind of covers how one might go about doing what you need: http://www.codeproject.com/KB/cs/propertyeditor.aspx