We we assume $V_1 = 1$ and $V_2 = 2$ then these two are in stack while traversing from 0. [ $V_1$ and $V_2$ are just names for two nodes existing in the stack ]
Under these assumptions, we can say that there is a directed path from $V_1$ to $V_2$. And there is no path from $V_2$ to $V_1$. ( both way path is not necessary )
But it is not necessary that always $V_1$ comes first in the stack. If we assume $V_2$ = 1 and $V_1$ = 2 , then is no path from $V_2$ to $V_1$.
One thing we can be sure that there is at least a path between $V_1$ and $V_2$ in one of the direction.