ShopSortByMultipleFields.cls

Shop shop = null;
List<Shop> shops = new List<Shop>();

/* Shop A */
shop = new Shop();
shop.name =  'A shop';
shop.address = 'Minato-ku, Tokyo, Japan';
shop.proceeds = 100000;
shop.category = 'sweets';
shops.add(shop);

/* Shop B */
shop = new Shop();
shop.name =  'B shop';
shop.address = 'Kita-ku, Osaka, Japan';
shop.proceeds = 110000;
shop.category = 'sweets';
shops.add(shop);

/* Shop C */
shop = new Shop();
shop.name =  'C shop';
shop.address = 'NewYork, US';
shop.proceeds = 90000;
shop.category = 'diy';
shops.add(shop);

shops.sort();
    
System.debug(shops);
    
public class Shop implements Comparable {
    public String name{get; set;}
    public String address{get; set;}
    public Long proceeds{get; set;}
    public String category{get; set;}
    
    public Integer compareTo(Object other) {
        // sort by category asc
        Integer categoryCompared = category.compareTo(((Shop)other).category);
        // next, sort by proceeds desc
        Integer proceedsCompared = categoryCompared != 0 ? categoryCompared : (Integer)(((Shop)other).proceeds - proceeds);
        // next, sort by address asc
        Integer addressCompared = proceedsCompared != 0 ? proceedsCompared : address.compareTo(((Shop)other).address);
        return addressCompared;
    }
}