How to start a hospitality design service?

Hi, I have a studio that do some design for residential, retail and office. In this space most of clients are from word of mouth and most of them only a local company.

So, I was wondering where do some 4-5 stars multinational hotel get their fancy design from? Do they source the designer in-house or they choose a design studio based on reputation and a fancy style? I have got no details on this, but for a 3 stars or similar boutique hotel, i know that some of hotels use a pooling and need a design samples by some studios. They will choose which one samples they like and made contract with the studio.