This is something I'm really curious about. Can a small commercial district be created *inside* an apartment building?…

This is something I'm really curious about. Can a small commercial district be created *inside* an apartment building? In Korea, commercial areas do form around apartment complexes. It's natural for businesses to pop up where people gather. However, these areas are usually formed around separate alleys or buildings, not the apartment buildings themselves. That's the difference I'm so curious about. Imagine having a barber shop, internet cafe, general store, or other small shops *within* an apartment building. It would be like Hong Kong's Kowloon Walled City...