many firebase project for a single android app.

I'm building an newspaper app. everything is made (logo, GUI). As the newspaper I have inserted a tablayout containing different volley (such as Politics, sport, culture etc..). the difficulties for me is to retrieve the data in the different categories of the app. I mean, I'm able to send date in the running app for only 1 category (Politics), and I'm not able to send real-time data to other categories. I'm using firebase database to send real-time data in the app for Politics side. I CAN'T create other database for others categories to put real-time data. I need a developer who will show me the way to use many firebase project for 1 Android app.