Let us consider a Directed Acyclic Graph $G(V,E)$ such that all edges have unit weight. Let $s$ be a source node, $s\in V$ and a set of destination nodes, $D\in V\backslash s$. My problem is to find a node $d\in D$ such that $d$ has a path of unique length $l>0$ from source node, $s$ to destination node, $d$ (i.e no other node in $D$ has a path of length $l$ from the source node $s$). There could be multiple destination nodes $d_1,d_2,...$ such that $d_1$ has a path of unique length $l_1$ and $d_2$ has a path of unique length $l_2$ from the source node and so on. How to find such nodes? Is there any algorithm or modification to existing algorithm to solve the problem?