Exponential of a function times derivative

The question is answered affirmative (and in a much simpler way) elsewhere: Summary. First solve the differential equation: $$ g(x) = \frac{1}{\phi'(x)} \quad \Longrightarrow \quad \phi(x) = \int \frac{dx}{g(x)} $$ Then we have (barring division by zero and other issues): $$ e^{g(x)\partial} f(x) = f(\phi^{-1}(\phi(x)+1)) $$ Update, triggered by another question (but where?)
By definition, for a function $\phi$ and its inverse: $$ y = \phi(x) \quad \Longleftrightarrow \quad x = \phi^{-1}(y) \quad \Longleftrightarrow \quad \phi^{-1}(\phi(x)) = x $$ From this, an elementary result in calculus follows: $$ \frac{dy}{dx} \frac{dx}{dy} = 1 = \frac{d\phi(x)}{dx} \frac{d\phi^{-1}(y)}{dy} \quad \Longrightarrow \\ \frac{d\phi^{-1}(y)}{dy} = \frac{1}{\phi'(x)} = \frac{1}{\phi'(\phi^{-1}(y))} \quad \Longrightarrow \\ \frac{d\phi^{-1}(x)}{dx} = \frac{1}{\phi'(\phi^{-1}(x))} $$ There is an application with the Lie series. We have: $$ u(t) = e^{t\,g(x)\frac{d}{dx}} x = \phi^{-1}(\phi(x)+t) \quad \mbox{with} \quad g(x) = \frac{1}{\phi'(x)} \\ u(0) = e^{0\,g(x)\frac{d}{dx}} x = x = \phi^{-1}(\phi(x)) $$ It follows that: $$ \frac{du}{dt} = \frac{d\phi^{-1}(\phi(x)+t)}{dt} = \frac{1}{\phi'(\phi^{-1}(\phi(x)+t))} = \frac{1}{\phi'(u(t))} $$ In short: $$ u(t) = e^{t\,g(x)\frac{d}{dx}} x \quad \Longleftrightarrow \quad \dot{u}(t) = g(u(t)) \quad \mbox{with} \quad x = u(0) $$