booya2nd

import * as path from 'path';
import * as url from 'url';

function forEachDeep(obj, cb, options = { depth: 6 }) {
  (function walk(value, property = undefined, parent = null, objPath = []) {
    return value && typeof value === 'object' && objPath.length <= options.depth
      ? Object.entries(value).forEach(([key, val]) =>
          walk(val, key, value, [...objPath, key])
        )
      : cb([property, value], parent, objPath);

booya2nd

const print = x => console.log(JSON.stringify(x, null, 2));

const animals = [
  { value: 'mammals', parent: 'animals' },
  { value: 'animals', parent: null },
  { value: 'poodle',  parent: 'dogs' },
  { value: 'dogs',    parent: 'mammals' },
  { value: 'labrador',parent: 'dogs' },
  { value: 'siamese', parent: 'cats' },
  { value: 'cats',    parent: 'mammals' },