Pull one product from inventory into multiple stores

Hi all,

I'm hoping someone might be able to assist.

I'm in the process of creating a website (hence why it may look a little chaotic at the moment) and was wondering if someone could help. 

I'm trying to pull products from one inventory, into three separate stores. I've set up a new arrivals and best sellers section as a store, and I'm hoping to pull selected products across from their own stores, into the two created to advertise best sellers and new arrivals. 

If anyone can assist, I'd greatly appreciate it.

thanks!