If your property is a campus with individual buildings, each individual building will be listed so that you can easily make all associations for the whole property all in one place. You will notice that meters created for individual buildings can be associated to the individual building AND to the parent property so that you do not have to create and maintain duplicate meters at the building and property levels. Meters created for one individual building cannot be reused for another individual building (i.e. sibling buildings may not share meters).
To illustrate how you would select metrics, say you have a hotel that consists of 2 towers (Tower A and Tower B). Tower A and Tower B are both separately metered for electricity, but they share a natural gas meter.
When you select meters for the Hotel Campus (parent property), you will select all three meters and say: they account for the total energy consumption.
But, if you are also benchmarking Tower A separately, then you would select only it's electric meter and say: it does not account for the total energy for Tower A.
Then another set of options would appear where they would select "Another Configuration," and enter something like "This is only the electric, this property also uses natural gas that comes from a meter that supplies several buildings and isn't submetered."