Output Multi Select Values from Custom Field with PHP

I’m trying to output the multiselect values I have from a custom field I created. I want to output it in a tab I created on the listing details page, so I would need to use some php. I’m trying to find out what code I would need to type. I know how to post it on the tab, what I can’t really do is make the custom field into an array and then output those values.

Thank you!