There are three buildings that are in two parts. An exterior and an interior.
You must put these pieces together perfectly for them to work properly. The best way to do that is to snap them together(see FAQ #3). Once you do that you need to assign the interior a Blink_parent so they can be seen from the outside.
While on the subject of snapable buildings. I would like to mention that there are two complete oil rigs in LW.
One is made of 25 pieces and looks like this...



While the second one is made of 15 pieces and looks like this...

The obvious differences are the support columns (the first looking like concrete and the second having a steal frame work) and lighting (the first has the light bulbs all over it for night missions while the second does not). Also the second one does not have the access ladder to get on it, on the smaller part of the rig.
But there are a few other differences that make the second one a whole lot easier to integrate in uneven terrain.
Well, with all that said here's an example of what it could look like in Egypt.

Or in the Rocky Mountains...