Here is my helper which is included in app.js and which is being called in mysql provider

app.js

var helpers = require('../components/helpers');
var app = express();
app.set('helpers', helpers);

components_helpers_index.js

exports.getConfig = function (configSubDirectory, configName) {

    var pathToConfig = __dirname + '/../../config/' + configSubDirectory + '/' + configName + '.js';

        if ( ! require('fs').existsSync(pathToConfig)) {
            console.log(pathToConfig, ' is not found!');

            return false;
        }

        return require(pathToConfig);

};

providers_mysqlProvider.js

createMysqlConnection = function (app) {
    var mysqlConfig = app.settings.helpers.getConfig('provider', 'mysql');

    if ( ! mysqlConfig) {
        return null;
    }

    return mysql.createConnection(mysqlConfig.mysqlParameters);
};