var address_id = 'fld-fb97220d3a4a4df48df4a54030766c54';
record.getFieldValue(address_id).match(/Cupertino/) ? 'Yes' : 'No';
You can use the method match on strings, it takes a regular expression which is why the string is in backslashes not quotes. I use a ternary operator to take the output of the match and do a ‘yes’ or ‘no’ based on if something was found.