Combine 2 mux output into 1 analog output

You can cascade multiple Analog-Muxe ...

What exactly want you to do?

And please change the title of your topic.

Software , it makes no sense ...

Here a example for cascading of Analog-MUXe.

If no I pressed then 0 mA.
If I1 pressed then 2 mA.
If I2 pressed then 4 mA.
If I3 pressed then 6 mA.
If I4 pressed then 8 mA.
If I5 pressed then 10 mA.
If I6 pressed then 12 mA.
If I7 pressed then 14 mA.
If I8 pressed then 16 mA.
If I9 pressed then 18 mA.
If I10 pressed then 20 mA.