Export feature offers users to define and export a particular set of your project data. In export options, you can also define that if you want only user stories, user stories with sub items or export only issues.

Be aware that Export fetches only items that are visible on the board. To export some selected User Stories, first define your user story criteria by applying filters on the board. Once your data is shown on the board, navigate to board´s:

Right Navigation menu, Settings Setting-Icon icon > Export as CSV

At Export dialog, you can choose between exporting user sroty only or its sub items as well. Select item fields, if you want only selected field values.

Note: Export will fetch only items that are visible on the Board at the time of export.