dynamically change values in datagridview combobox columns

HI,
i have 3 combobox columns in datagridview,when i change value in 1st combobox column
then 2nd combobox column should fill with corresponding values,and by changing 2nd combobox value then 3rd combobox column should fill with corresponding values.how can i do this?

Ex:
first combo box column: Category
display members: A,B,C
second combo box column:Products
display members:a,a1,a2 b,b1,b2 c,c1,c2

when i select 'A' in combobox1 ,then 2nd combobox should contain\display a,a1,a2 only not others
and when i select 'B' in combobox1 ,then 2nd combobox should contain\display b,b1,b2 only not others

Plese answer if anyone have solution