In this paper, we present two novel methods to handle the fusion of multiple Bayesian Network knowledge fragments which we termed N-Combinator and N-Clone. In DSO National Laboratories, we have developed a cognition based dynamic reasoning machine called D’Brain capable of performing high level data fusion. Knowledge is encapsulated in D’Brain as Bayesian Networks knowledge fragments. D’Brain is dynamic in its reasoning mechanism that resembles human reasoning, where the knowledge structure is ever evolving with the different sources of observable inputs. N-Combinator and N-Clone are the methods used in the dynamic reasoning mechanism. Experiments have shown the good performance of these two methods.