multi_tz accepts a format argument where you provide the desired template.
Between {} provide the target timezone.
> multi_tz -t "{BCN} | {BUE} | {EDT} | {CHI}"
20:32:08 | 15:32 | 14:32 | 13:32
Add the following function to ~/.p10k.zsh.
function prompt_multi_tz(){
content=$(multi_tz -t $HERE_GOES_YOUR_TEMPLATE)
p10k segment -f 6 -i 🌎 -t ${content//\%/%%}
}
Under POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS, comment out time and add multi_tz
typeset -g POWERLEVEL9K_RIGHT_PROMPT_ELEMENTS=(
...
# time # current time
multi_tz
...
)