iTerm2のドキュメント、恐ろしくあっさりしている
Initial Directory Normally, new sessions begin in your home directory. You can choose to open new sessions in the same directory as the current session (but only when creating a new tab), or you can specify a starting directory.
Advanced ConfigurationでNew Windows/New Tabs/Split Panesの時のディレクトリも調整できる qiita.com
