Drop down Lists to pull data

[starry436]

I would like to be able to pull and combine data using drop down lists..so for example, I want to analyze financial information on my properties all combined as well as individually. So in my drop-down list say I have these to choose from:
ABB LLC (combined)
Apple Street
Gold Street
Blue Street

So those are listed in my drop down box, now I want to be able to select ABB LLC and have it pull data from all 3 of those properties and give me totals. Additionally, if I just select one property, Apple Street, I want to only see data pertaining to it. I also want to be able to say I only want to see combined data on Apple and Gold streets and be able to select them from the drop down and have their combined data display.

Can anyone help me on how to get, started? Is this possible? Basically I want to be able to combine any of my 50 properties and get data output individually or combined. My financial software cannot combine properties to show overall totals. I'd have to pull the Financials on each individual property and add them up manually.
Also, I'd like to make the data interactive on the web, so if I want to be able to send the drop down Lists to someone and they can select properties to view totals.