You can bring in modules from different javascript file using require based javascript code, or normal Babel parse-able imports. But the code with these imports often become a little bad because of relative imports like:

import Component from '../../path/to/Component'

But a better, more cleaner way of writing ES6 imports is

import Component from '~/path/from/jsRoot/Component'

This hugely avoids the bad relative paths  for importing depending on where the component files are. Now, this is not parse-able by babel itself. But you can parse this by webpack itself using it's resolve attribute. So your webpack should have these two segments of code:

resolve: {
        alias: {
            '~': __dirname + '/path/to/jsRoot',
            modernizr$: path.resolve(__dirname, '.modernizrrc')
        },
        extensions: ['.js', '.jsx'],
        modules: ['node_modules']
    },

and

module: {
        rules: [
            {
                test: /\.jsx?$/,
                use: [
                    {
                        loader: 'babel-loader',
                        query: {
                            presets: [
                                '@babel/preset-react',
                                ['@babel/preset-env', { modules: false }]
                            ],
                        },
                    }
                ],
            },
}

The {modules: false} ensures that babel-preset-env doesn't handle the parsing of the module imports. You can check the following comment in a webpack issue to know more about this.