first.jsx

class UserDetail extends Base {
  render () {
    let { user } = this.props;

    return (
      <strong>{user.name}</strong>
    );
  }
}

function mapStateToProps (props) {
  return { user: [['user'], function (userList) {
    return userList.find((user) => {
      return user.get('id') === props.routeParams.id;
    }).toJS();
  }] };
}

const ConnectedChild = connect(mapStateToProps)(UserDetail);
export default ConnectedChild;

second.jsx

class UserDetail extends Base {
  render () {
    let user = this.props.user.toJS();

    return (
      <strong>{user.name}</strong>
    );
  }
}

function mapStateToProps (props) {
  return { user: [['user'], function (userList) {
    return userList.find((user) => {
      return user.get('id') === props.routeParams.id;
    });
  }] };
}

const ConnectedChild = connect(mapStateToProps)(UserDetail);
export default ConnectedChild;