I am using boost property_tree in my program. I\'ve set up the tree for using custom path type. What I\'m looking for is getting a specific node\'s parent node id.
Here
You can't.
Boost Ptree nodes are self-contained and do not know about any containing datastructure (it's the the "tree" equivalent of a singly-linked list).
As a best approximation you could look up the child inside the parent, e.g. with something like in C++: boost ptree relative key.
This presumes you always have "a root" available to search in.