It goes to "In +". Remember to connect the output back to "In -" or it won't be unity gain. Basically what you're doing is duplicating the top part of the schematic, but using the pin numbers on the lower symbol. The power supply part is already taken care of, so its basically 3 resistors and 2 caps you need. Just make sure you connect the 1M resistor like the fully drawn out version of the schematic indicates. Thats what the "To Other Channel" note is for.