nginx - preserve bookmarks on domain move

We're moving a website from www.xdomain.com to www.ydomain.com

It's primarily a forum, with many topics.

Therefore it would be common for someone to bookmark e.g.

http://ift.tt/2f7vgw9 or something.

Our goal is to have a seamless transfer from one domain to the other (currently we have both domains pointing to the same folder in hosting), but we would prefer this to happen:

http://ift.tt/2f7vgw9 redirects to http://ift.tt/2fte4jv

i.e. the ONLY changes is BEFORE the .com - all the subfolders are exactly the same and compatiable.

Is this possible to do? If so, how could I do it in nginx? The main reason is for bookmarks AND to force the use of our new domain.

Thanks.