Question about hip bands

Hello fellow retro sewers!

I have a little question for you. I'm making a dress for which I don't really have a pattern. I'm using another pattern as a basis and modifying it. It's a drop waist dress and I was thinking of adding a hip band, as seen for example on this pattern (Advance 7043):

The thing is that I don't have at home any pattern with such detail, so I'm not sure how it's made.
It seems most of the time it's a straight band cut in the bias, but not always. And from looking at the pictures, it doesn't look like it's attached to the bust at the top. I was thinking maybe it's just sewn at the waistline at the same time as the skirt... But then if the seam allowance it going upward at the waisline, I would think the band would fall down if it's not held in place at the top.

I was wondering whether maybe someone had done this before or had a pattern including a hip band, and could scan the instructions or describe how it's made. That would be really helpful!

Thank you for reading and have a nice day!

~Lholy-chan from Amelie no mori~