how to find in mongoose code example

Example 1: findbyid mongoose

// Find the adventure with the given `id`, or `null` if not found
await Adventure.findById(id).exec();

// using callback
Adventure.findById(id, function (err, adventure) {});

// select only the adventures name and length
await Adventure.findById(id, 'name length').exec();

Example 2: mongoose where

exports.generateList = function (req, res) {
    subcategories
            .find({})//grabs all subcategoris
            .where('categoryId').ne([])//filter out the ones that don't have a category
            .populate('categoryId')
            .where('active').equals(true)
            .where('display').equals(true)
            .where('categoryId.active').equals(true)
            .where('display').in('categoryId').equals(true)
            .exec(function (err, data) {
            if (err) {
                console.log(err);
                console.log('error returned');
                res.send(500, { error: 'Failed insert' });
            }

            if (!data) {
                res.send(403, { error: 'Authentication Failed' });
            }

            res.send(200, data);
            console.log('success generate List');
        });
    };