[?] Take n times gradient from a vector?

Questions
1

Hi. Suppose we have a vector V with two variables x and y.
How to take n times gradient from this vector by using Mathematica? Please help me.

2

If I try to interpret what you ask, then you probably mean “how to recursively evaluate the gradient of a function with a vector”; then:

foo[v_] := (* do something *) v^2
n = 3;
v = {x, y};
Nest[Grad[foo[#], #] &, v, n]
3

Thank you very much.