Try to devise XOR gates (exclusive-OR). A stack of them creates a one-dot graph effect as you need.
I suppose you realize you could start with a window comparator made from several op amps. This makes a bar graph, however this method turns on several indicators at a time. So you also realize you need to add a method to select one and only one indicator.
XOR circuits made from transistors can be seen at the website below. It may be possible to adapt these to your design.
https://www.4qdtec.com/dlc.html