Each of those commands are invoked as a separate session when you use the waithidden cmd.exe command, so your input does not carry over from one session to the next.
If you wanted to run multiple CLI commands at once, you can do this using the & operator; note that & will error out if the previous command failed, while && will process all of your commands regardless of exit state.
waithidden cmd.exe /c command 1 && command 2
Note that you need to invoke either /c or /k when running cmd.exe, at least in my experience.
That being said, in this case you can use the __Download relevance substitution instead of CD’ing to the folder. Simply run
Remember, each invocation of cmd.exe knows nothing of preceding or following invocations, so in your example the second one does not inherit the current directory that was set for the first.
You do need to test using the debugger and if a command needs to have the working directory explicitly set you need to look at running a small batch file (that you can either cache on the server and download or create on the fly in the actionscript).