I’ve been searching for how to do nested prefabs (placing one prefab inside another without losing the original connection) and found various claims that it was going to be in Unity 5, but nothing recent. Is that possible yet? I’d prefer not to have to fork out cash for a plugin that does something that’s about to be added for free.
AFAIK, this is one of the most requested features, but it is not implemented yet (not in Unity 5 or even Unity 5.1).
You can vote for this feature request here: http://feedback.unity3d.com/suggestions/editor-nested-prefabs