How are sourcemaps resolved?

I’m trying to get source maps working with Sentry for a reactjs application. I’m using webpack in conjunction with the SentryWebpackPlugin. The relevant configurations in the webpack config look like this:

const SentryWebpackPlugin = require('@sentry/webpack-plugin');

const SentryOptions = {
  // sentry-cli configuration
  authToken: process.env.SENTRY_AUTH_TOKEN,
  project: process.env.SENTRY_PROJECT,

  // webpack specific configuration
  include: pathLibrary.resolve(__dirname, '..')

module.exports = {
  devtool: 'hidden-source-map',
  output: {
    filename: '[name].[contenthash].js',
    chunkFilename: '[name].[contenthash].js',
    publicPath: '',
    path: pathLibrary.resolve(__dirname, '..', 'public'),
    sourceMapFilename: '../tmp/sourcemaps/[file].map'

if (DEPLOY_ENVS.includes(env)) {
  module.exports.plugins.push(new SentryWebpackPlugin(SentryOptions));

When I build and deploy the application, I can indeed see source maps and sources in Sentry, however, the code shown on the issues page does not appear readable. This leads me to believe that I have done something incorrectly with naming the output files or source maps.

Another thing potentially worth mentioning is that the bundled application is hosted on and referenced from S3, in a different directory structure than what is built in webpack (ie, not /public).

I guess I’m trying to understand how my webpack output and sourcemaps should be named so that sentry can map errors to the right place.