Thanks Sujay. Interesting video. Thanks for pointing me to this. Seems like he mentioned that this functionality is not yet available.
I am still of opinion, there should be a way we can do this.
As I explained in my scenario, applying data source filters for last 12 months etc will not work as it will re-create data extract from data source which has only last 1 month data i-e will remove all data and have only last 1 month to start with.