The second strand, COMING FROM THE TOP RIGHT, crosses the first: underneath, twice on top, then underneath.
From there, now represented by a line, it weaves the pattern thus created.
(Note that this second strand, like the first, is no more than a single knot: this pattern is the combination of two single knots, all in the way they are interlaced)
Now add this knot, more or less openwork according to your taste.
You can cut off the four ends and sew it onto a fancy jacket, for example, in the style of a brandebourg.