Best Product per Client

Hello.

I have two tables. One with clients. One with sales.

I want to create 3 columns in my clients table.

First column: Name of the product in which they spent the most money.

Second column: Name of the product in second place.

Third column: Name of the product in third place.

To clarify: I need the results to show the product in which the client spent the most money overall. So, for example, if a client spent 20€ on boots  and 50€ on 10 t-shirts, it should say t-shirt, even tho boots are more expensive than t-shirts.

Besides that, I need to filter the sales table since I don't want all transactions to be considered. Let's say I want to filter by ProductCategory. 

Thank you in advance.