I travel with a 2 wheel rollaboard bag and a small laptop bag.
Typically, I have my laptop bag strap the perfect length so I can give it one twist and put it around the extendable handle bars such that it hangs down my rollaboard without touching the floor.
This gives good counter balance so I can pull my bag with little downward weight while letting me let go and not have my laptop bag rest/slide on the floor.

Sometimes I travel with a smaller 2 wheel bag that's maybe half the height but same thickness and width. Even if I set the strap of my laptop bag to its shortest length and twist it 4 times, it's still a little too long and kind of unstable.

I see FA's have a strap that seems like it's attached to the handle of their rollaboard bag with a hook where the handle of their bag can go in.

Where can I find something like this? Either something with a hook or something a short strap with a buckle that I can just loop.
Ideally something inexpensive