The survey for practical consideration is crucial in social and policy science inquiries. Several systematic reviews in the post-conflict peacebuilding literature have thus far ignored its efficaciousness. This knowledge gap motivated in developing ConflictAffected Population Survey technique to survey the conflict-ravaged Chittagong Hill Tracts indigenous peoples for the purpose of examining peace hybridity in Bangladesh, as the quantitative part of the study. This article outlines guidelines for designing probabilistic sampling and survey procedures for a robust sequential explanatory mixed-methods case study research in a terrain where an accurate sample frame is difficult to define. The systematic methodological strategy adopted herein enabled the compilation of a comprehensive cross-sectional case study where findings are generalizable, especially the concept and model central to our thesis on indigeneity dilution.