The logic you have says:
Get all regular categories, loop through them and in each category fetch the current posts categories then get just the last category object and fetch the custom field of that category.
What exactly are you trying to do? Do you want to display the current posts categories or do you want to display all categories as links(or without links)?
Welcome to the Advanced Custom Fields community forum.
Browse through ideas, snippets of code, questions and answers between fellow ACF users