You can't. What you can do is create a table in the script with the bookmark id's and names and a category field. You can use that table to let users select a bookmark and use an ApplyBookmark action assigned to the OnSelect field trigger of one of the bookmark fields to activate the bookmark. In essence you're creating an alternative menu for the users to select a bookmark. The disadvantage is that you will have to create that bookmark table in advance and user bookmarks can't be part of it.