I unlocked this achievement through natural online play as it was one of the first maps I played on while going for other achievements. There are a limited number of maps, so it will come up eventually. As far as I know, there is no way to make it come up faster naturally. There are the map preferences, but I felt like they never worked for me. If you want to try prioritizing them anyway, go to Play Online > Find Match > and then press
to vote on map preferences. The map is called Champions Field in the preferences menu, not Celebration Field like the description suggests.
If someone can confirm that it can be unlocked in a Private Match, that would be awesome. I got it right away so I can't test it out or I would.EDIT:
According to UtG Mist, this can't be done in a Private match, meaning you have to play online until you happen to get the map.