Do you mean specificity? Granuarity means a finer level of detail, but here you're not talking about that, really, you're talking about a finer level of specification IMHO.

So, plz change to "Further specificity can be achieved by", or possibly even better, change the style so it's more approachable:
"If you'd like to be more specific about exactly which objects your registered factories should be injected into, you can do so in the following manner:"