Is there a way to put a particle emitter on a particle?

for example, if I want to make a fire ball with fire particle coming out from the ball while it is flying I will need to put a emitter on the ball itself to emit particles. But I don't see any option to attach another particle emitter to the particle itself. I guess there should be a way to doing this but I could not find any answer online.

 

by the way is there a way to put a group of particle system in one sub emitter slot? I tried to drag the parent effect in there but the unity tell me to reparent which separate the parent particle emitter to the rest of its child emitter, so if I want to make a complex effect for the projectile I will have to put each of the effect and their child effect in the slots one by one, is there a easier way to do this?