Version: 2017.3
public static Object GetPrefabParent (Object source);

説明

ソースの親アセットオブジェクトを返し、見つからない場合は null を返します

Use this function to get a prefab asset object the source was instantiated from. This also returns the prefab parent if the prefab has become disconnected, which can then be used to reconnect the prefab.