Did you read the description over at SparkFun? SparkFun Analog/Digital MUX Breakout - CD74HC4067 - BOB-09056 - SparkFun Electronics
You have to connect 4 pins from your nodemcu to the select lines of the breakout board and the signal pin on the breakout board to an analog input pin. By setting your address pins, you select channel 0 to 15 to connect to your signal pin which you then read. If you look at it in binary, it looks like this:
S3 S2 S1 S0
0 0 0 0 = channel 0
0 0 0 1 = channel 1
0 0 1 0 = channel 2
0 0 1 1 = channel 3
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