Great question — answering as the UphillTech team:
Google my business has separate categories for "Primary Business" for each site: Each site gets the advantage of having its own unique Google knowledge graph that area that shows up at the right of a search for a company. And Google my business, listing which feeds Google map and the knowledge graph. https://support.google.com/business/answer/7249669?hl=en each of which has benefits for businesses in that category. IE: A hotel has free online booking an gets listed in the travel pages, https://support.google.com/hotelprices/answer/10684696?hl=en Restaurants get online menus, https://support.google.com/business/answer/9455840?hl=en There is a category for wedding venue....
Full answer by Wayne Smith: https://webmasters.stackexchange.com/a/142148 (CC BY-SA 4.0).
Need it done for your business? UphillTech.