Unnamed bus connections in schematics
You're right, it isn't clear. It would be interesting to see the netlist produced from that schematic.

However, we can infer a few things about the application.

It's a "GAL/ATF Blaster", and it would seem that IC1 and IC3 are the sockets into which you put the device being "blasted". Only one will be occupied at a time.

Furthermore, the O[0..9] bus is simply connected to a pack of pulldown resistors, and the only purpose seems to be to ground the unused outputs on the device being programed.

Therefore, it's probably safe to assume that each pin gets its own pulldown, and that it's safe to connect the same pulldown to a pin on both sockets.