 <p>This maybe a difficult one for someone with limited Alfresco knowledge, so hopefully you'll understand it.</p> <ol> <li>You'll need to create a repository webscript which takes as input a site and uses siteService methods to get the members and groups. You can peak at the siteMembers Share page which probably uses something similar to show the members and groups. And you'll probably will need to make it searchable :).</li> <li>Change the current custom control which uses the default picker to select users/groups. Probably you'll only need to change the repository webscript url so it goes to the right new webscript. If you don't want to make any more changes, be sure to present the output in the exact same way.</li> <li>You can start a workflow from you personal dashboard of from the my-workflow pages, so there is not always a site. And even if you're starting from a site big changes the site doesn't get passed to the start-workflow page. So you'll need to get the destination nodeRef (the node you're starting the workflow on) send it as param to your repository webscript and let it determine which site it is in.</li> </ol> <p>First change the custom control which selects the assignee. This control goes to a repository webscript which shows/searches all the users/groups.</p>