Hi,
you would need to create a custom search result of searching only in tags, i.e.
customize a standard web part.
To the search string you would need to add automaticaly a condition to search only in DocumentTags.
Example:
If the user would like to search for car and bike, you need to add +DocumentTags:(car bike). See
search syntax for more details.
Moreover, the key
CMSSearchOnlyWhenContentPresent has to be set to false.
If you need to search only in tags, there is a
tag cloud web part. Maybe it could meet your requirement as well.
Best regards,
Ivana Tomanickova