How to simplify the following functional derivative?

Question

I have to simplify the functional derivative: $$ \frac{\delta}{\delta f_{k}(\boldsymbol{x}',t)}\delta(\boldsymbol{x}-\boldsymbol{\xi}(t))$$ where $\delta(\boldsymbol{x}-\boldsymbol{\xi}(t))$ is a Dirac Delta function, $\boldsymbol{\xi}(t)=[\xi(t)\;,\xi_{2}(t)\;,\ldots\;,\xi_{n}(t)]$ is a dynamical vector with n components and satisfies the equation $\frac{d\xi_{i}(t)}{dt}=v_{i}(\boldsymbol{\xi},t)+f_{i}(\boldsymbol{\xi},t)$.