Add NVM's working directory to your $HOME path (if it doesn't exist):
mkdir ~/.nvm
Copy nvm-exec to NVM's working directory
cp $(brew --prefix nvm)/nvm-exec ~/.nvm/
Add the following to $HOME/.bashrc, $HOME/.zshrc, or your shell's
equivalent configuration file:
export NVM_DIR=~/.nvm
source $(brew --prefix nvm)/nvm.sh
Type `nvm help` for further information.
Bash completion has been installed to:
/usr/local/etc/bash_completion.d