If you want the parent to overlap the child, then the child can’t be a child, they’ve got to be siblings of the same parent. Each child nesting defines a new layer id for the batcher, and in turn defines the necessary z-order things must render in. You’ll need to structure this some other way, either by using 1 image, and doing the compositing in a material to permit an irregular mask to be applied. Or to do it using an Overlay panel, where the “child” is at index 0, and the “parent” is at index 1, so that the parent border is overlapping the “child”.