You can set owners , assignees , candidate users and candidate groups . These attributes are passed on to the User Tasks contained within the lane. That way, you could for instance easily model that all tasks are shared within a certain group without having to set the Candidate groups attribute on every task of a lane.
above content how to do ??? not find any method to implement
You can use a variable like ${assignee} and use it accross different usertasks to make sure you assign it to the same assignee (and similar for candidateGroups/owners/etc.) for consecutive tasks.