wkLnv‖Choose Format - Arrange - Send Backward (LibreOfficeDev Writer, LibreOfficeDev Calc).
yfLSs‖Choose Shape - Arrange - Send Backward (LibreOfficeDev Draw).
uc68f‖CommandCtrl+minus sign (LibreOfficeDev Impress, LibreOfficeDev Draw)
D2F6v‖Open context menu - choose Arrange - Send Backward (LibreOfficeDev Impress).
BQhNe‖