To avoid confusion, these are the bra hooks I was referring to. These days you're more likely to find them sewn into pre-made strips of hooks that you just attach to your bra. If you can't find them in a sewing supply shop or your grandmother's sewing basket, then what I do is just cut them out of an old bra that's no longer wearable
Hooked Together?Sewing With Hooks & Eyes | Yesterday's Thimble