"the Dynamic Mind (is concerned with) the putting out of mental forms for realisation of the idea"
The Dynamic Mind can be compared in part with Conation in Faculty Psychology, and - were one to use or continue the "fractal" approach of the Gurdjieff-Ouspensky-Bennett system - the Emotional subdivision of the Intellectual subdivision of the Intellectual Center. No doubt other correlations could be found as well. According to Sri Aurobindo the dynamic mind manifests through the brow (Ajna) chakra.
The following further quotes of Sri Aurobindo are from the "Divine Plan" website (no longer online)
The true inner consciousness is a silent consciousness which has not to think out things, but gets the right perception, understanding and knowledge in a spontaneous way from within and speaks or acts according to that. It is the outer consciousness which has to depend on outside things and to think about them because it has not this spontaneous guidance.
Intellect, will, etc. are intermediaries which try to catch something of the hidden higher truths and bring them into life or else raise life to them so that the possibilities of life here may become the complete realities that are already there above.
But now he walks in Nature's doubtful ray.
Yet can the mind of man receive God's light,
The force of man can be driven by God's force,
Then is he a miracle doing miracles.