Here is a Wikipedia article that provides an example of the structure you want, providing four examples of how the placement of an apostrophe can change the meaning of a sentence:
http://en.wikipedia.org/wiki/Apostrophe
* My sister's friend's investments (the investments belonging to a friend of my sister)
* My sister's friends' investments (the investments belonging to several friends of my sister)
* My sisters' friend's investments (the investments belonging to a friend of several of my sisters)
* My sisters' friends' investments (the investments belonging to several friends of several of my sisters)
Unfortunately, the article does not go into detail about the structure itself, but the examples themselves come from a reliable source (Steven Pinker).