Choose Format - Arrange - Send to Back (LibreOfficeDev Writer, LibreOfficeDev Calc).
Choose Modify - Arrange - Send to Back (LibreOfficeDev Draw).
Shift+ComandoCtrl+Sinal de menos (no LibreOfficeDev Impress e no LibreOfficeDev Draw)
Open context menu - choose Arrange - Send to Back (LibreOfficeDev Impress).