No (but there are workarounds).
No, connect and connect:amp have a single line in. You could use a (pre) amplifier to select an analog source and connect the line-out or tape record out of that amplifier to your Connect. If that amplifier is software controlled then you can select the input from a remote location. It will however not be integrated in the Sonos app.
Another way would be to add another Sonos device with a line in (Connect, Connect amp, or Play:5), and connect your CD player to that device, that makes you can choose which line in to use from the Sonos app.
In both ways you can connect multiple analog devices to the line in of your Connect amp. If you stay with a single line in device, you should however ask yourself how useful a software line in choice will be: you have to put a CD in the CD player and press play so you are already near the Connect amp. How much extra effort would it take to select the CD player on the (pre) amplifier?
Regards,
Erik