Tiny Unity3D editor script to create a new GameObject at selection. Invoke with Alt+N.

CreateEmptyAtSelection.cs

using UnityEngine;
using UnityEditor;

public class CreateEmptyAtSelection : ScriptableObject {

	[MenuItem("GameObject/Create Empty at Selection &n")]
	static void CreateEmpty() {
		GameObject go = new GameObject();
		
		if (Selection.activeTransform != null) {
			go.transform.parent = Selection.activeTransform;
			go.transform.localPosition = Vector3.zero;
			go.transform.localRotation = Quaternion.identity;
			go.transform.localScale = Vector3.one;
		}
		
		Selection.activeGameObject = go;
	}
}

Здесь не обязательно наследоваться от ScriptableObject , достаточно пустого статического класса.