How to make these gift bags

[RockingMyFiftiesNot]

I would like to make some gift bags with the drawstrings a little down the bag, ribbons pulled on either side to gather and tie in a bow at the front (see stills from video of similar). Whenever I've made drawstring bags, the strings have been on one side of the bag and drawn to that side. I can't work out how the strings draw on both sides? Not sure I've explained that very well! Hopefully the pics will make clearer

I have organza bags like this. At the top is a 'channel' through which the ribbon drawstring material runs. There are two strings, one with the knot to the left, the other with the knot to the right.
Not sure if I have explained that terribly clearly.

two strings, one draws tot he left, the other to the right the result is as in the pic.

I think Riftgibbon has described it quite well, two ribbons/strings fed in from opposite sides

Thank you - obvious when you think about it, feel a bit daft now