gistfile1.js

const fieldList = [
  { label: 'Foo Fields', fields: [{name: 'foo', selected: false}] },
  { label: 'Bar Fields', fields: [{name: 'bar', selected: true}] }
]

fields: Ember.computed('fieldList.@each', function() {
  let fields = []
  this.get('fieldList').forEach((config) => {
    config.get('fields').forEach((field) => {
      fields.push(field);
    });
  });
  return fields;
}),

enabledFields: Ember.computed.filterBy('fields', 'selected', true);