How many entry-exit permits are required to fly from the mainland to Macau, then to Hong Kong, and finally return to the mainland from Macau?

If it is a one-time trip, you only need to endorse Macau once and Hong Kong once or multiple times. You can choose it yourself on the machine.
Two trips to Macau and one trip to Hong Kong. If you are a Shenzhen resident, there is no problem. They can generally travel to Macau multiple times a year.
If you arrive in Macau from the Mainland and obtain a seven-day stay permit, and travel to Hong Kong and return to Macau within the seven-day stay permit period, you only need to apply for a Macau endorsement once!
According to the regulations of the Hong Kong Immigration Department, if the itinerary sequence is Mainland → Hong Kong → Macao → Hong Kong → Mainland, and the total stay in Hong Kong and Macao does not exceed 7 days, the Macao leg is considered an “incidental itinerary” and only Hong Kong is required , Macao endorsement once each. If the trip is within 7 days, only 1 Hong Kong endorsement and 1 Macao endorsement are required. If the trip exceeds 7 days, 2 Hong Kong endorsements and 1 Macao endorsement are required.