Good question, since the settings are very misleading.
To my knowledge, it is not possible to directly save to pdf as you are hoping to do. However, there is a bit of a workaround that will still let you embed a vector graphs from Open/LibreOffice in your LaTeX documents:
- Select and copy (ctrl+c) your graph.
- Open LibreOffice Draw
- Paste your graph from Calc into Draw
- Select the graph, and go to
File --> Export
, select EPS
from the list of formats, and make sure the selection
box is checked:

I haven't tried the other formats, but EPS should play nicely with your LaTeX document, or you can easily convert your EPS to PDF and insert them.
Here is a side by side comparison of trying the export setting with PDF (left--ends up centered on the page) and EPS (right--exports just the graph).
