I believe it was in the first double weave episode, Season 8, Episode 4, in the 9th video (the Show & Tell). It was with the first piece shown, 4-shaft shuttle hanger. If you search Lee Valley for "bar handle" you'll get lots of options, mostly narrow but some are wider, such as those for larger cupboard or closet door handles.

I hope this helps!

I attached mine to the side of a cabinet, the one that holds my bobbin winding station, some favourite yarns, etc. Were I to attach it to a wall I would use a piece of wood a little bigger than the bar handle, painted to match either the wall colour or to coordinate with the woven piece I was hanging, then nail or screw the wood to the wall. But mine ended up on the cabinet, so can be moved with the cabinet if I rearrange the room.