Filter a custom field based on another custom field
We are a global company with various regions such as LATAM, NORAM, EMEA, ITAL, NOBA, APAC etc. When someone selects the region(s), we want them to be able to select the countries that apply to the project request for the selected region(s). Is there a way to do a mapping table of sorts or to filter custom field options based on selections made within a custom field? Can this be added?