Let \((X,d,\mu )\) be an RD-space satisfying the doubling condition in the sense of Coifman and Weiss and a certain reverse doubling condition. In this setting, the authors first investigate a weighted John–Nirenberg inequality for the space \(\textrm{BMO}_{\theta ,\varphi }(X)\) introduced in Lu, G.; Wang, M.: Characterizations of spaces \(\mathrm BMO_{\theta ,\varphi }(X)\) on RD-spaces., which extends some known results on \(\textrm{BMO}\) -type spaces on Euclidean spaces and RD-spaces. Furthermore, some useful characterizations of spaces \(\textrm{BMO}_{\theta ,\varphi }(X)\) are established.