JSFiddle - React, Tailwind, and code Playground

by phaas

JavaScript

var map = {
    'A': [{
        'id': 'a1',
        group: '1'
    }, {
        'id': 'a2',
        group: '2'
    }, {
        'id': 'a3',
        group: '1'
    }],
        'B': [{
        'id': 'b1',
        group: '1'
    }, {
        'id': 'b2',
        group: '2'
    }, {
        'id': 'b3',
        group: '2'
    }]
};

console.log(map);

var tmp = _.reduce(map, function (memo, value, key) {
    memo[key] = _.groupBy(value, 'group');
    return memo;
}, {});

console.log(tmp);