New in Tableau 2021.2,  use the 'Rename Fields' option to rename multiple fields in bulk. Search for parts of a field name to replace or remove it, or add prefixes or suffixes to all or selected fields in your data set. You can also automatically apply the same change to any fields added in the future that match your criteria by selecting the Automatically rename new fields check box when making your changes.

Find out more at the following link.