First of all you should understand the main type of application that you are willing to develop. You're having a web application, (develop using ASP.NET) and now what you are going to develop is a service (not to be confused with Web Services) under the same web application that you have already created. Services include (as an example),
- Users -- for Authentication purposes
- Chat and posts -- for updates
- Bla bla -- for other gibberish purposes...
There are other enormous types of services that your web application would support. It depends on your, for what type of services you would want to support and allow. Each of these services can be associated with their own database, which would hold objects (tables) and other stuff (attributes, stored procedures etc.) to run your
model-based processes. It is upon you to use which database for which service. If this is a
Model-view-controller based pattern, then you should know that your Controller always allows you to hold control over the response being streamed down to the client.
You have only provided us with a sample sketch of your View (perhaps a layout file) and we have no idea what your application is, what it would do in those other three services... And so on. Anyways, still you can use different (
three) controllers to get the data from different sources and fill up your view for the user to use.