i∗ is a goal oriented requirements engineering tool that can model varied requirements for solutions being developed by an enterprise. Different stakeholders within an enterprise may use partial or even completely non-intersecting vocabulary sets. This would lead to developing multiple i∗ models having independent ontologies. Collectively, these i∗ models define a requirements refinement hierarchy where different tiers of the hierarchy capture different levels of detail. In order to integrate such a distributed ontology, we require an appropriate mapping or correlate definitions between different ontologies at multiple levels. This paper tries to identify different types of bridging correlations that allow an integration of multi-ontological i∗ refinement hierarchies. We use these correlations to demonstrate how relative completeness can be established between adjacent tiers of the hierarchy. Varying degrees of relative completeness have also been identified and their fulfillment criteria have been summarized as theorems. A University Admissions System has been used as a case study to illustrate heuristics for achieving greater relative completeness.