Do you mean like the ‘more’ category here:
We’ve typically been moving away from using those, as we find that generally kids have an easier time scrolling than noticing the new category / remembering which is in which. If you want to use it, though, it’ll pop up if you annotate a block with
//% advanced=true
If I recall correctly,
//% subcategory="something"
will make one labeled as ‘something’ instead of ‘more’, but I’m not certain on that / whether that’s been used.