Hi, 

- One option is, you can add that to the product search view. So that when you enter the supplier name, it will show only products of that supplier, which you can then export to excel.

For eg, in the xml view file you can add the following:

<record id="product_search_form_view_inherited" model="ir.ui.view">
            <field name="name">product.product.search.inherited</field>
            <field name="model">product.product</field>
            <field name="inherit_id" ref="product.product_search_form_view"/>
            <field name="arch" type="xml">
            	
            	<field name="name" position="after">
             		
             		<field name="name" string="Supplier" filter_domain="[('seller_ids.name.name','ilike',self)]"/>
             	</field> 
            </field>
        </record>

- Other option is to create a new report, which allows you to choose the supplier and then give a pdf report containing the supplier and its products details.

- If you just need to categorize the products based on supplier, you can add a Group_by supplier in search view.

I have the same request.

The answer from Akhil is not useful to me since I don't know how and where to enter this code.

Nevertheless I find it important to add this additional search criteria on the supplier/customer.
Can some have a look at this?
Regards,

Karel