The 4051 in the configuration shown in the figure can be used as a selector of both analog and digital data present in the inputs, passing them to the output according to the code placed in select. If the signals are digital, pin 7 must be grounded and if they are analogue, they must be supplied by a symmetrical source with pin 7 connected to -5 V. The signals must be of low intensity with amplitude less than the voltage used in the circuit supply.
