So if you want limit the visibility of an api to an internal application team, you have just to create an internal application team role in wso2 console(configure/user and roles) and write it when you create your api.
When people with this role will be connected to the store, they will see this api. But other people can't see it.
you can limit the visibility of api to roles.
On the first page of api creation, you can select visibility and put it to restricted by roles.