Position relative to its parent box: Black Box
position: absolute;
top: [bigBoxTop]px;
left: [bigBoxLeft]px;
Position relative to its parent box: Blue Box
z-index lower than z-index of sibling box: Box2
position: absolute;
top: [smallBoxTop1]px;
z-index: 1;
Position relative to its parent box: Blue Box
z-index lower than z-index of sibling box: Box1
z-index same as earlier sibling box: Box1
position: absolute;
top: [smallBoxTop2]px;
z-index: [zIndex];