The photoluminescence properties of dopants are strongly correlated with their distributions in host phosphors, the knowledge of which, however, is not well established yet. In this paper, the distribution of the active dopants, for example, trivalent ytterbium (Yb3+) and bivalent nickel (Ni2+) in a highly transparent germanate glass-ceramic containing thermally grown Zn1+xGa2-2xGexO4 (0x1) nanospinels, is revealed by an analytical transmission electron microscope. The elemental mapping and linescan analysis confirm that both Yb3+ and Ni2+ accumulate preferentially in the germanium-substituted ZnGa2O4 nanospinels embedded in the glass. The influence of glass crystallization on the electric transition properties of Yb3+ is presented. An enhanced ultrabroadband near infrared emission of Ni2+ is observed as a result of efficient energy transfer from Yb3+ to Ni2+ accumulated in the nanocrystals. Discussions are given to account for the detailed mechanisms of the efficient energy transfer occurring between the dopants.