How to connect two current sensors together?
It's not clear how you ever thought this would work. You haven't provided a link to the module datasheet but if they are analog out then connecting them together would create a problem if they're trying to output different analog voltages.



simulate this circuit &ndash; Schematic created using CircuitLab
Figure 1. A simple diode arrangement can detect the highest input signal.
This may be adequate for an analog input but remember that you'll have a voltage drop across the diodes.
It might also work if the analog voltages are high enough to exceed the threshold voltage of the GPIO.