How to use

pickBy

function

in

ObjectChain

const bib = _.chain(iso_639_2).pickBy((v, k) => v['639-2/B'] === k).values().value().length;
const ter = _.chain(iso_639_2).pickBy((v, k) => v['639-2'] === k).values().value().length;
console.log(`${ter} languages + ${bib} bibliographic = ${values.length} entries`);