What the solution for this? please help. Thank you so much
Simplest and most straightforward way to achieve your goal without writing a module is to add custom attribute on product, filterable in layered nav, which will keep the information about type of a product. So add new attribute to your attribute set, and fill this attribute with required options. Then you will be able to filter results by product type.
Otherwise you will have to customize layered nav and i doubt that anyone will write a whole module for you here..