How can I know the top users for a specific tag? For example, Java. Means, I want to filter the "Users" tab with java tag.
Check this (when hovering with the mouse over a tag)
The last line of the popup shows the link
Or you can enter this url http://meta.stackoverflow.com/tags/tag_name/topusers
You can hover over the tag, which opens the mouseover thingy. Bottom Right Option is Top Users.
Alternately, in the queue for questions (example) you have a link called Top Users - nestled between Improve Tag Wiki and Synonyms.