which hive to combine with?

[Michelle]

Here is the dilemma, I made a split and it swarmed 5 weeks ago. I caught the swarm and it was softball sized. It has only made 3 frames. Do I combine it back to the original split? The original split is only 1 deep and a honey super (that's all I had for them to expand before my vacation) All the other hives are going great.

[efmesch]

If you are pleased with the laying performance of the caught swarm's queeen, I would recommend uniting the swarm with the original hive.  This leaves you with a single hive with a young laying queen. 
Reorganize the combs in such a way as to encourage building your unbuilt foundation (which will only take place if you've got a flow going on).  Move the unbuilt foundation to either side of the brood area, with built frames closer to the hive walls.  If it means taking out some built frames to give them room, you can save them for when needed on another occasion.  This situation is one of those instances when having different sized frames presents an inconvenience.

[LazyBkpr]

Here is the dilemma, I made a split and it swarmed 5 weeks ago. I caught the swarm and it was softball sized. It has only made 3 frames. Do I combine it back to the original split? The original split is only 1 deep and a honey super (that's all I had for them to expand before my vacation) All the other hives are going great.

  Well said Ef.
  Sounds like you answered your own question. if all the other hives are doing great, then the best place for the swarm is back to the split.
   (Why did they swarm?)
  Would be the question.. it wont do much good to recombine if the brood area is plugged out with honey or pollen...   I would also mention being crowded, but if the swarm was that small, I am thinking crowding was not the reason, unless it is a cast (secondary) swarm??