This paper deals with the optimization of the mass of geodesic dome structures, taking into account different schemes of member grouping. Using fewer groups of struts with different cross-sections may be attractive from the perspective of production, transport, storage, and execution costs. However, too few separated cross-sections in the structure result in higher construction material costs (steel) and an overstated total mass of the structure. Using the same cross-section for all strut elements also results in unused cross-sections, leading to additional unnecessary costs. The task of grouping elements is a long-term process, requiring multiple attempts to isolate the optimal number of strut element groups in the analyzed structures. The paper analyzes two innovative geodesic domes, based on a regular octahedron. It presents a set of interesting results on displacements, internal forces, stresses, and the structure's mass for various schemes of grouping dome elements. Based on research conducted to date in this area on various construction objects, this paper demonstrates the validity of member grouping for geodesic strut domes with different grid topologies. Carrying out this process is necessary primarily because of the structure's total mass reduction.