explanation -
hierarchy points to the parent objects and the iteration is the default
D = starts at 1 level down
N = iteration path is next on same level
hierarchy outputs each object in turn, and object index gives the index number 0, 1, 2 etc
capsule is a representative object that assumes the ID of whatever is plugged into object port
the index is compared to the slider
== gives a True or 1
!= gives a False or 0
the visible ports -
0 = on
1 = off
2 = default
so the value is inverted with the not node