Investigation of experimental observables in search of the chiral magnetic effect in heavy-ion collisions in the STAR experiment * *Supported by the US Department of Energy (DE-AC02-98CH10886, DE-FG02-89ER40531, DE-FG02-92ER40713, DE-FG02-88ER40424, DE-SC0012910, DE-SC0013391, DE-SC0020651), and the National Natural Science Foundation of China (12025501, 11905059, 12075085), the Strategic Priority Research Program of Chinese Academy of Science with (XDB34030200), the Fundamental Research Funds for the Central Universities (CCNU19ZN019), the Ministry of Science and Technology (MoST) (2016YFE0104800) and the China Scholarship Council (CSC), Join Large-Scale Scientific Facility Funds of NSFC and CAS (U2032110), the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, within the framework of the Beam Energy Scan Theory (BEST) Topical Collaboration, the U.S. National Science Foundation (PHY-1913729), the Natural Sciences and Engineering Research Council of Canada, the Fonds de recherche du Qué