Small businesses often just hire people they know and trust, which just seems like sensible risk mitigation.
But what about if the business keeps growing this way (above "small business" thresholds)? e.g. The owner only hiring people he discovers, and after that's infeasible, his highest trusted managers. I'm thinking of situations where you come to understand the skills somebody has and you say "Hey! You'd be really good at helping out with X work. You want a job?". You already know the person is timely, respectful, "fits the culture" etc.
To say another way: the business never advertises, but instead only invites individuals to work for them. It could even include a non-discriminatory screening interview to check suitability for the business' goals.
I can't find any information in any jurisdiction about discrimination related to selecting individuals for employment and "creating a role to fit"
Added later: I think it helps if you let go of capitalism and the idea that an organisation's purpose would be to maximise it's profits by generating valuable goods.
Think instead of an organisation that was founded with charitable intent and the business' value creation is of a more intangible manner: behavioural / relational / mental / spiritual.
Imagine a Third World charity requiring personal alignment / investment: sponsoring a child perhaps.
Or an anti-depression organisation requiring everybody to be kind and sensitive - even for less visible/interactive jobs like lawyers and accountants.
I'm pretty sure these criteria would be discriminatory in a advertised position.
I happen to be in New Zealand, but this really is theoretical.