How do I enstantiate objects within a cluster?

I want to spawn multiple enemies at once at a randomized position, but I want them to spawn close together, how would I do this?

You could make some empty game objects and place them around your scene, then add them to an array in some kind of manager script, and choose between these points with a random number. These would then act as spawn points where you could spawn your prefabs.

If you want it totally random, you could probably make a script with a width and height value for your scene, that you then loop through, and for each index, you spawn multiple enemies by offsetting the value by a small amount on either the z or x-axis.