I'm making a redesign for a website that sells bespoke versions of 12 insurance products to 12 different types of businesses, supplemented with information also specific to the type of business. The old site currently has a separate page for each business and their associated products, so a lot of pages.
The problem: It's possible for one company to encompass multiple types of businesses, leading to them having to view 3 separate pages about essentially the same product just because the business activities overlaps. This lead to a lot of confusion (understandably) because people got confused about which product fit their situation and which they had to request.
To counter this, we want to make a site-wide filter that allows people to select their business activities and based on that, we generate only information applicable to their business and situation. We would essentially only have 1 page per product, instead of 12. My question is: Are there any best practises for a site-wide filter? When is it appropriate to ask people for their information (business activities), straight away or contextual based on actions like selecting a product? And which shape fits the purpose the best, full screen or part of the page? Any examples would be highly appreciated.