How can I show list of users that bookmarked article?
If you really want to do this with Views you will need the following:


A Content View for articles
with a Nid as a Contextual Filter, in order to limits the results to the article node you are interested in
one relationship that will restrict your results to content that has been flagged with the bookmark flag (by any user)
one relationship that will return all users that flagged content using the flag from the relationship in (3).


Here is a Screenshot of the View:



and one of the end-result, in a sample node:



Hope this helps!