@pichalite said:
@sanatisharif actually I was wrong... you can move multiple posts from a topic and create a new topic. It's actually called forking. It's under the "Topic Tools" drop down in the topic page.
Thanks a lot, its good idea also after that we need some plugin on nodebb to merge topics:
https://community.nodebb.org/topic/7225/how-to-merge-topics-in-admin