རྒྱབ་ལུ་གཏང་།

Choose Format - Arrange - Send to Back (LibreOffice Writer, LibreOffice Calc).

Choose Shape - Arrange - Send to Back (LibreOffice Draw).

Shift++ཕབ་རྟགས་ཀྱི་ཨང་རྟགས་ (LibreOffice Impress, LibreOffice Draw)

Open context menu - choose Arrange - Send to Back (LibreOffice Impress).