The possibility of an alt-history Cold War in which Nazi Germany and Imperial Japan replaced the USA and USSR is...fairly counterfactual to put it mildly (and that's not even considering the role of Fascist Italy). However, as regards immediate post-war plans between Tokyo and Berlin had they been victorious (in similar style to Man in the High Castle) - as well as Nazi plans for the rest of the world post-conquest, see this thread with contributions from u/Georgy_K_Zhukov, u/ryamano, and myself.