Here's my code:

void MeasurementModePage::setupListView()
{
    QString protocolsPath = "D:/";
    qDebug() << QCoreApplication::applicationFilePath();
    qDebug() << QCoreApplication::applicationDirPath();
    qDebug() << protocolsPath;
    listmodel = new QFileSystemModel(this);
    listmodel->setRootPath(protocolsPath);
    QStringList filters;
    filters << "*.xml";
    listmodel->setFilter(QDir::NoDotAndDotDot | QDir::Files); // To be removed in case folders have to be also displayed
    listmodel->setNameFilters(filters);
    listmodel->setNameFilterDisables(false);
    listmodel->sort(0, Qt::AscendingOrder);
    ui->listView_measurementFiles->setModel(listmodel);
    ui->listView_measurementFiles->setRootIndex(listmodel->index(protocolsPath));
    connect(this, &MeasurementModePage::settingsChanged, this, &MeasurementModePage::onSettingsLoad);

    // Context menu
    ui->listView_measurementFiles->setContextMenuPolicy(Qt::CustomContextMenu);
    connect(ui->listView_measurementFiles, &QWidget::customContextMenuRequested, this, &MeasurementModePage:: showCustomContextMenu);
}

void MeasurementModePage::on_listView_measurementFiles_doubleClicked(const QModelIndex &index)
{
    // Load an XML settings file if the index selected is a file
    if(listmodel->fileInfo(index).isFile())
    {
        // Load settings with external LIB
        emit settingsChanged();
    }
}

On a side note: I would like the root path to be set to a folder where my application is built, where I will place some XML files for the users to choose from. Does it make sense to read it using "QCoreApplication::applicationDirPath();"?