Abstract
Spherical fuzzy soft expert set (SFSES) theory blends the perks of spherical fuzzy sets and group decision-making into a unified approach. It allows solutions to highly complicated uncertainties and ambiguities under the unbiased supervision and group decision-making of multiple experts. However, SFSES theory has some deficiencies such as the inability to interpret and portray the bipolarity of decision-parameters. This work highlights and overcomes these limitations by introducing the novel spherical fuzzy bipolar soft expert sets (SFBSESs) as a powerful hybridization of spherical fuzzy set theory with bipolar soft expert sets (BSESs). Followed by the development of certain set-theoretic operations and properties of the proposed model, important problems, including the selection of non-powered dam (NPD) sites for hydropower conversion are discussed and solved under the proposed approach. These problems mainly focus on the need for an efficient tool capable of considering the bipolarity of parameters, complicated ambiguities, and multiple opinions. Supporting the new approach by a detailed comparative analysis, it is concluded that the proposed model is more comprehensive and reliable for multi-attribute group decision making (MAGDM) than the previous tools, particularly considering the bipolarity of parameters under SFSES environment.