This stitch follows a technique where the rows of chevron stitches are overlapped to create and effect.

To follow this tutorial, you need to know the chevron stitch.

Fig 1: Make row of chevron stitch, depicted in black thread here. Now, impose it with another row of chevron stitch, depicted in orange thread. Fig 2: Only, this time, the second row of chevron stitch will fill up the open spaces left by the earlier chevron stitch.
Fig 3: Finish up the entire row, as shown. Fig 4: A finished row of double chevron stitch looks like this.