Depends on the grocery store and how large of a player it is, and how well it thinks it can anticipate consumer demand, and cross-market across the entire store, etc. Both the distributor and the grocery stores have sales figures for the products, per-store, so it's a matter of who is best at crunching the numbers.

When I used to live in Stockholm, my closest grocery store was one of the big two chains in Sweden, and they had "outsourced" part of their shelf re-stocking to the distributors, so if you went there in the mornings, you could have one or two people from a big bread producer/distributor restocking half the bread section, and you'd have someone from a different producer/distributor doing half the candy section (probably someone from Mondelez). I don't know this for sure, but I would bet that the distributor had a lot of leeway on how to restock the shelves using their own sales data.

Right now, my local Safeway has a bunch of shelves of deli products, but it's all Boar's Head products. Five bucks says that Boar's Head is choosing how to stock those shelves, and not Safeway. They also sometimes have a little floor display promoting new products from Boar's Head, that's also something that the local Safeway didn't do, they were just served up with some ready-to-go marketing, and they're okaying it.