You can use the following shortcut keys in charts.
You can also use the general shortcut keys for LibreOffice.
Select next object.
Select previous object.
Select first object.
Select last object.
Move the object in the direction of the arrow.
Moves the selected pie segment in the direction of the arrow.
Enter text input mode.
Open group so that you can edit the individual components (in legend and data series).
Exit group (in legend and data series).
Reduce or enlarge the chart
Moves the selected pie segment off or into the pie chart.