A distributed directory service for an online services network comprises multiple, separate services (Directory Service Providers) runs on application servers and provides access to a respective hierarchical directory structure. Nodes of directory structures representing online services may be accessed by end users of the network. Junction point nodes provide usertransparent links between the different directory structures which appear to end users as a single hierarchical directory. A common application program interface (API) implemented by the Directory Service Providers allows client applications to access the different directory structures using a common set of software methods. Data items shared by multiple nodes are optionally stored by the Directory Service Providers within a shared database and can be accessed via special API methods. Nodes are selected for display to end users using various forms of node filtering at the Directory Service Providers.