In the example, 3 loops are worked on. The 3rd loop on the left is passed over the 2 loops on the right.
(loose loop)

The first of the 2 loops passing through is knitted flat.

The bottle yarn is increased by wrapping it once, and the second stitch next to it is knitted flat.

Knit 1 stitch, knit 3 stitches, purl 1 stitch...the row is completed like this. On the back of the knitting, all the loops are purl knit.

For example, finished. By repeating the triple process in 3 rows, coffee beans are formed.