@SaidaRaoGampala That's what I meant by my previous post. You would have to create a standalone user group which would be used in the workflow participant step. If you add additional user group as part of this group, it means that group users will also contribute the workflow activites.
If you assign the step to an entire group, then when the workflow reaches this step all users & user group part of this group will have the action in their Workflow Inbox.