Inside folder multichain-other there is a folder with the name of your chain. In your case it is "node1".
Inside this folder there is a file: multichain.conf
Edit this file and set port and rpc port. Example:
port=10255
rpcport=10254
Then instead of:
multichain-cli -datadir=.multichain-other node1
use:
multichain-cli -datadir=.multichain-other -port=10255 -rpcport=10254 node1