I suggest to add the link “https://help.libreoffice.org/6.4/en-GB/text/scalc/guide/cellreferences.html” for more helpful information around the topic “Referencing other sheets” to the documentation “To specify a data range”.
Changing component to Documentation
Please explain the steps you want to achieve. It appears not possible to have a data range directly from another file, except by pasting the data into cells in the file that holds the chart.
(In reply to Olivier Hallot from comment #2)
I would appreciate helpful descriptions for functionality which is partly explained by an information source like the following.
Support for referring to tables from external files