Custom view on data

I created two custom post types - Company and Item. I established a relation between them using Posts2Posts plugin. What is the best, most correct way to create a template/view displaying all the items of a company.

Wordpress created this URLs for me: site/company/company_1 and site/item/item_1 . I want a link of format site/companies_items/company_1 which would display all the company_1's items.

Thank you for your time.