As an example with the apartment rentals data, let's say that you want to compare the area (size in square feet) of all apartments with the average size of an apartment for the building. It's fairly easy to get the area per apartment:
In the preceding figure, the view level of detail (the level of detail defined for the view) is Building and Apartment because those are the dimensions in the view. So, the average area is calculated per apartment, per building.
It's also fairly easy to get the average area per building, by simply removing the apartment dimension from the view, like this:
But what if you want to work ...