Recently I had a request from UCL Australia for a reference from one of my former masters students who was applying to do a PHD. I had never heard of "UCL Australia", and in checking I found it is the Australia arm of University College London (a highly respected institution). However, the Australian operation is based in the Torrens Building, 220 Victoria Square, Adelaide. UCL have a photo of this building with their flag out the front, but I was sure the building was associated with another university.
A web search found the Carnegie Mellon University Australia is also located in the Torrens Building, as is Torrens University Australia. All three of these institutions feature photos of the Torrens Building on their websites. Both UCL and CMU have photos of the building, each with only their own flag out the front. CMU Australia also show photos of teaching facilities and a video.
It is not clear if each institution has its own teaching facilities in the building, or are sharing them. Having shared facilities would be good for the students, but would be a little misleading if each institution to fails to mention that, and so implies they have the building to themselves.
Of course, universities are not the only ones which recycle buildings in this way. The Australian government has an impressive looking military command centre, which appears in the media with different names and functions attached to it.