current_instance

Set the current instance, alias of 'set_inst'
Usage: current_instance($instance);
$instance: Set $instance as the current instance.
         If the argument is missing, return the current setting
         ".." set to parent module, "~" set to the most top level module 
Note: It can be reset to the root top module by 'undo_eco'. It has same effect of 'set_top' and 'current_design'