There is no simple way to do this currently, but we are thinking of permitting this in the future.
Currently, your best solution is to copy the whole project.
Regarding your other problem, you would benefit greatly from the concept of partition, we have a tutorial that can help you getting started here. Please check out our tutorials portal, partitioning is part of the advanced section https://www.dataiku.com/learn/portals/tutorials.html
I see, but copy the whole project pretty bad. It store to same database. For example, project A > copy to > Project A2 When I change recipes in A2 it will store data to same A database, all data in project A will change, too. This means I have to change inputs and outputs in every recipes...... That really consume time to do them.