From The Document Foundation Wiki
Follow these steps:
- Go to ▸
- In the dialog that appears, select the file type Text CSV.
- Check Automatic file name extension.
- If the file has not been saved before, give it a name.
- Click on Save.
- Confirm that you really want to use this format (you will lose formulas, formatting, graphics...).
- In the next dialog Export text enter the Field delimiter that you want. The default is a comma. The Text delimiter is the character that separates each data entry in your spreadsheet when it is converted to ASCII format.
- Click on OK.