After reserching for a while it's still not clear how can I do this.
I would like to grant read access to specific users to specific records.
Let's say i have products in categories and I want to grant read/write access to product A for user User1 or read only access to User1 for products from category2. If the user doesn't have read access he shouldn't see those records.
I have to be able to create my own access groups and assign users to them, and on my products should be able to assign access groups
How do I achieve such a behavior?