The Assign option is only available for entities which base type is Base Request.
User Level permission () for Assign option means that user of the role only can view and set oneself and own groups as Assignee for the selected entity. For example, if you defined User Level scope for Request then user can only see oneself and own groups as options of Assignee dropdown list in Request form.
Group Level permission () means that user of the role can view and set only selected groups and members of those groups as Assignee for the selected entity. When you select a Group Level and right click the symbol, a popup opens enabling you to select group(s) from the available, active groups in the system. If single group or multiple groups but not all are selected, then image icon will be surrounded by orange border. If all groups are selected then image icon will be surrounded by green border.
Organization Level permission () means that user of the role can view and set only members of the user’s organization and their groups as Assignee for the selected entity. Similar to Group Level, if Organization Level is selected and you right click the symbol, a popup is opened where you can select organization(s) from available, active organizations in the system. If single organization or multiple organizations but not all are selected, then image icon will be surrounded by orange border. If all organizations are selected then image icon will be surrounded by green border.
System Wide permission () allows user of the role to view and set active Agents of the entire system as Assignee for the selected entity.