How do I pass a slice of data in another slice type

I would like to now how to return sliced data at a top level but also have the ability to use the function. The pointer reference is required to use the function but i have no idea how to cast the sliced data to the reference.

type User struct {
  Id:   int
  Name: string
}

type Users []User

func (u *Users) SomeFunc() bool {
  // Do something
}

Usage below

func run(u []pkg.UserData) *Users {

  users := make([]User, 0)
  if len(u) > 0 {
    for _, val := range o {
      // DO Mapping
    }
  }

  return users
}

I tried making users a struct and have a child key called Users which worked fine, but i need the data at a top level and not nested. I assume i would have to do something like return &Users{ //something } but i have no idea what to do.