Dear Vaibhav, how do I move from focusing on a single object to focusing on multiple objects?
You need to transition from focussed attention to peripheral awareness.
Stop paying attention to objects for a bit. Really relax into the sense of being here. Then fall back into awareness meaning move from the front of your headspace more towards the middle and simply allow it to relax downwards. You can do this by sucking you inner eyes back towards the middle of the headspace and then allowing the inner eyes to relax.
Simply breathe and relax. Allow all the various objects to come to you.
You are now embodying awareness to which all objects report.
It will take some work but you should see start seeing results in a few weeks. Eventually this will become your new meditative home.