you don't need separate jog file ...

[alec-c4]

... you can just add following to your .zshrc file

function jog {
  grep -v "jog" ~/.zsh_history_ext | grep -a --color=never "${PWD}   " | cut -f1 -d"⋮" | tail
}

function zshaddhistory() {
  echo "${1%%$'\n'}⋮${PWD}   " >> ~/.zsh_history_ext
}

[alec-c4]

I've improved a bit (added sort and remove empty lines and duplicated commands)

function jog {
  grep -v "jog" ~/.zsh_history_ext | grep -a --color=never "${PWD}   " | cut -f1 -d"⋮" | grep -v -e '^$' | tail | sort | uniq
}