The following circuit diagram is designed for stereo channel selector. It uses for connecting stereo outputs from four different sources/channels as inputs and only one of them is selected/connected to the output at any one time.
Here a quotation from the article:
These switches are connected to four separate channels. For stereo operation, two similar CD4066 ICs are used as shown in the circuit. These analogue switches are controlled by IC CD4017 outputs. CD4017 is a 10-bit ring counter IC. Presets VR2 and VR3 have been included for adjustment of individual audio threshold levels of left and right stereo channels, as desired. Once the multivibrator action of IC1 is disabled, output of IC2 does not change further. Hence, searching through the channels continues until it receives an audio signal exceeding the preset threshold value.
Find more information about the Stereo Channel Selector Circuit Diagram here (source: Electronic-Circuits-Diagrams.com)