Hello @ridhosay,
Product Filter by WBW takes Attribute values ??directly from the WooCommerce product database and cannot change them on the fly.
You can change the Attribute values ??in the product properties themselves, but this will result in them changing the data type from digital to string data type.
Usually, units of measurement for a filter section are described in the Describe field, which displays the text next to the section directly or in the Title of the section.