Write for harp double stave

How can I write a scale or an arpeggio that goes through the 2 staves without make them look separated, but connected. For example, when I try to do something like the image (excerpt from Mahler’s 4th) I need to put rests where there are no notes in each stave. I can make a fluid arpeggios or scale, they all stay separated. Is there any way to do something like the image?