How to cite more than one equation in align environment

With the code you showed, in fact, only the first of the three equations is labeled. You need to add a label for each of the equations that you want to reference.

documentclass{article}  
usepackage{newtxtext, newtxmath}
begin{document}
begin{align} 
    label{components-endomorphism-curvature-1}
       tilde{R}_{ABCD} = R_{ABCD}, 
       tilde{R}_{0ABC} = 0, 
    label{components-endomorphism-curvature-3}
       tilde{R}_{0A0B} = e^{2f} left( overline{nabla}_A overline{nabla}_B f + overline{nabla}_A f overline{nabla}_B f right).
end{align}
Here are references to eqref{components-endomorphism-curvature-1} and eqref{components-endomorphism-curvature-3}. 
end{document}