All you need to understand here is how the relation between the 3 tables works, then in the Combobox.SelectedIndexChanged you have to check the ParentBO.Count > 0, so if there is a record, then you can sent the ParentBO.PKFieldValue to the first parameter e.Parameters(0).Value = Me.ParentBO.PKFieldValue.

In the Categories Combobox SelectedIndexChanged use this code:

Also I believe it is better to use sample with your real entities name, even if it is in Spanish, this way it will make more sense when posting real code .

Thanks for all your support. I still trying. If your have some simple sample, will be very good?

I think that in the ListPopulating should go the:

If Me.DetalleSubcategoriasBO.Count > 0 Then

e.Parameters(0).Value = Me.DetalleSubcategoriasBO.IdStio

Else

End If

And in the SelectedIndexChanged the Requery()

Regards.

All solved. Thanks a lot for your help.

Everything is possible, just keep trying...