Is there a braille symbol to represent a time derivative of a vector? The instructor represents this concept in the following way: for vector p, the letter p with an arrow pointing to the right on top, and, centered above that, a dot (of the sort used to indicate multiplication between two elements).
Without seeing a print example, I can only guess, but your description sounds like what the Nemeth code calls "Modifiers of Higher Order" in Section 87. Use the 5-step rule for transcribing modified expressions. The arrow will be the first order (modified directly over) and the dot will be the second order (two directly-over indicators). Use a contracted arrow and dots 16 for the dot.