Restricting search results in Knowledge Base to current category

As a Knowledge Base user, I want the search results only to show results in the current category, to avoid long search results and irrelevant articles.

My company has currently about 6 different products, which all are being documented in different categories in our Knowledge Base. All articles are public.

Most of our clients only use 1 of our products. Our clients are usually not aware about the existence of our other products since these are not relevant for them. This makes many of the categories and articles in our knowledge base irrelevant for our clients. Our clients use directlinks to the right category from each product.

When a user opens a specific product (=category) in the knowledge base, performing a search will show results in all products (=categories).

Logged in as a knowledge base editor with full permissions in all categories, searching is restricted to the current category. We would like the same behaviour for our clients.

Use case:
As a user of product A, I open the knowledge base category for product A.
I search for articles containing the words ‘logging in’.
The search results show articles about logging in in product A, product B, product C etc.
I am only interested to see articles about product A.