They grow as one stem. Those are four trees in one pot. Some on this forum would say to keep it as is. I Recommend separating now before the roots get any more entangled.

I don't know if I want to do that this year (?) I just bought it and it was very yellow from lack of ferts/nitrogen, and I just repotted it. Do you think it would be ok to do that this year yet? On top of that, I'm out of pots!

It is totally your choice. I personally would separate them ASAP but if you prefer to keep them as is...... If something goes wrong with watering, all four will be lost if in one pot but what are the chances they get killed with too much water if separate? one might show signs early and gives you time to correct. Just thinking out loud ;)

This comes up a lot here. If you have different varieties in one pot, the answer is always to separate; there are many reasons for that, but let's just accept it. If there are multiple plants of the same variety, there are NO cultural or practical reasons to separate; the ONLY question is do you want one tree/bush, or do you want 4.