Flattenezmagic

gistfile1.js

var data = [
    { name: 'a', other: 'ignore me', sub: [{name: 'a1'}, {name: 'a2'}] },
    { name: 'b', sub: [{name: 'b1'}, {name: 'b2', another: 'ignore me too'}] }
];

// Wanted: ['a', 'a1', 'a2', 'b', 'b1', 'b2']

// Flattenezify!

_.chain(data).map(function (d) {
    return [d.name].concat(_.pluck(d.sub, 'name'));
}).flatten().value()

// Ok, but what if sub can be null?

var data = [
    { name: 'a', other: 'ignore me', sub: [{name: 'a1'}, {name: 'a2'}] },
    { name: 'b', sub: [{name: 'b1'}, {name: 'b2', another: 'ignore me too'}}] },
    { name: 'c', sub: null },
];

// Wanted: ['a', 'a1', 'a2', 'b', 'b1', 'b2', 'c']

_.chain(data).map(function (d) {
    return [d.name].concat(d.sub ? _.pluck(d.sub, 'name') : []);
}).flatten().value()