Example for Connect by Prior

 Select  from_widget_type,Connect_By_Root To_Instance Target,

  SYS_CONNECT_BY_PATH(to_instance||'.'||to_field_name, '/') "Path" From ET_DUMP A  Where A.Mapping_Id=235

 Start With A.To_Widget_Type=2 

 Connect By NOCYCLE   Prior A.Mapping_Id=a.Mapping_Id

 And Prior A.From_Instance_Id=a.To_Instance_Id

 And Prior A.From_Widget_Type=A.To_Widget_Type

 And Prior A.From_Widget_Id=A.To_Widget_Id

 and prior A.From_field_id=a.to_field_id