From the confd_lib_lib man page:
struct confd_cs_node *confd_find_cs_root(int ns);
When schema information is available to the library, this function returns the root of the tree representaton of the namespace given by ns, i.e. a pointer to the struct confd_cs_node for the (first) toplevel node. For namespaces that are augmented into other namespaces such that they do not have a toplevel node, this function returns NULL - the nodes of such a namespace are found below the augment target node(s) in other tree(s). See confd_types(3).
struct confd_cs_node *confd_find_cs_node(const confd_hkeypath_t *hkey- path, int len);
Utility function which finds the struct confd_cs_node corresponding to the len first elements of the hashed keypath. To make the search consider the full keypath, pass the len element from the confd_hkeypath_t structure (i.e. mykeypath->len). See confd_types(3).
struct confd_cs_node *confd_find_cs_node_child(const struct confd_cs_node *parent, struct xml_tag xmltag);
Utility function which finds the struct confd_cs_node corresponding to the child node given as xmltag. See confd_types(3).
struct confd_cs_node *confd_cs_node_cd(const struct confd_cs_node *start, const char *fmt, …);
Utility function which finds the resulting struct confd_cs_node given an (optional) starting node and a (relative or absolute) string keypath. I.e. this function navigates the tree in a manner corresponding to cdb_cd()/maapi_cd(). Note however that the confd_cs_node tree does not have a node correspond- ing to “/”. It is possible to pass start as NULL, in which case the path must be absolute (i.e. start with a “/”).
Since the key values are not relevant for the tree navigation, the key elements can be omitted, i.e. a “tagpath” can be used - if present, key elements are ignored, whether given in the {…} form or the CDB-only [N] form. See confd_types(3).
If the path can not be found, NULL is returned, confd_errno is set to CONFD_ERR_BADPATH, and confd_lasterr() can be used to retrieve a string that describes the reason for the failure.
One reference you can use is the print_modifications() in this example: