type Position struct {
 X int
 Y int
}

type Colour struct {
 R byte
 G byte
 B byte
}

type Rectangle struct {
 Position
 Colour
 
 Width  int
 Height int
}

r := Rectangle{/* ... */}

// This works:
fmt.Printf("%d,%d\n", r.Position.X, r.Position.Y)

// but so does this:
fmt.Printf("%d,%d\n", r.X, r.Y)

type FooService struct {
 URL string
}

type BarConnectionOptions struct {
 URL string
}

type BarService struct {
 BarConnectionOptions
}

type Options struct {
 FooService
 BarService
}

opts := Options{
 FooService: FooService{URL: "abc.com"},
 BarService: BarService{
  BarConnectionOptions: BarConnectionOptions{
   URL: "xyz.com",
  },
 },
}

fmt.Println(opts.URL)