Mulitplexer to read analog values
You can use the above circuit.
One of the input in connected to output based on the selector line value.
selector pins decide which input line is connected to output line. selector lines = 000 selects HS1, 001 selects HS2 and so on.. 
You have to use time division multiplexing. ie., read HS1 for 1st few ms, read HS2 for next duration and so on..