Back 4 Blood

The fastest way to load hives (and start with a good amount of cards) is to run the first level of act 3, as it has more potential spawn points for hives than the first mission. It’s completely random for which hive you’ll get, and if you don’t get a spawn you can just back out to the camp area and try again. However, this can be done on the easiest difficulty. You do not need to own the DLC to unlock this, just play with someone who does.

The special case with The Nursery is it’s a hive that only appears WITHIN another hive, so there’s a little more RNG involved with getting it to spawn. Just keep searching regular hives for a hive entrance, as it can spawn anywhere on any hive.

Here is the secret location in The Nursery, courtesy of GDP Duncan.