How does the SANE stack represent parent/child relationships on a single model

How do I represent a parent/child relationship on the same model?

An example of this is a model representing a folder. A parent folder can have many children folders. But a child folder can only have one parent folder.

Ember.js has the concept of reflexive relations. I would like to implement the first option.

"... explicitly define the other side, and set the explicit inverse accordingly ..."

How would I go about setting that up on the sails.js side of the SANE stack?