I don't even know if community is the right word.
What I mean is if someone creates a gym, a friend creates a health bar on top of it, while another creates a sports clothing store.
what is this called.
Yes I do have friends right now that are trying to set up this type of thing.
Any knowledge of setting up a business would be useful.
If one person owns the business, then it could be a licensing agreement whereby the gym's brand name is licensed to the health bar and clothing store since the brand name is worth something. In this event, the other businesses pay royalties/license fees to the owner of the brand trademark and in return use the brand name to attract customers and turn over their inventory to net income. The inventory they procure is often up to them, as is how the sell, price, market and retail the product. However, some license agreements can be more stringent than others in terms of marketing agreements. It varies.
If the gym name is a corporate name and corporate owned, then the other two opportunities could be franchising opportunities. In this case, the health bar and sports store pay an up-front free to the gym owner to secure the brand name. Then, through a contract, they are obligated to buy product from corporate and follow certain marketing guidelines, and in exchange, they use the brand name to draw in customers and turn over product they're purchased at a margin attractive enough to net income.
It could also be a partnership between all three, with each acting at various levels of ownership depending on shares owned. These can be unlimited or limited liability partnerships. Depending on the structure of the organization.