* A group of people: This could be a work team, a social group, a family, or any other collection of individuals. Without more information, we can't know what they do.
* A specific organization: Some organizations or businesses might have groups numbered "seven" for internal purposes. Again, we'd need more context about the organization to know their occupation.
* A group of chemical elements: In chemistry, Group 7 is known as the halogens. They are nonmetals and are highly reactive.
To help me understand what you mean, please provide more information about "group seven".