Available on Asset Store: https://www.assetstore.unity3d.com/en/#!/content/112837

Forum Thread: https://forum.unity.com/threads/asset-usage-detector-find-references-to-an-asset-object-open-source.408134/

This editor extension helps you figure out at which places an asset or GameObject is used, i.e. lists the objects that refer to the asset. It is possible to search for references in the Assets folder (Project view) and/or in the scene(s) of your project. You can also search for references while in Play mode!

• Import AssetUsageDetector.unitypackage to your project
• Open Window - Asset Usage Detector window, configure the settings and hit GO!
  • or, right click an object and select Search For References

• You can search for references of any object that extends UnityEngine.Object
• Extensive search algorithm that uses SerializedObject and reflection to find references
• Can search in multiple scenes at once
• Can show complete paths to the references or only the most relevant parts of the paths (see the demonstration below)

• static variables are not searched
• GUIText materials are not searched
• Textures in Lens Flare's can not be searched