SQL & PL/SQL

i have a hierarchical data stored in a table , i want to get the level 2 object regardless of parameter i pass in the where clause of my select statement, for example i may pass level 3 or level 4 object but it must allways return level 2.

[code]

create table machine_mast(mch_code varchar2(12),mch_name varchar2(200),parent_mch_code varchar2(12),mch_level varchar2(12)); 
 insert into machine_mast(mch_code,mch_name,parent_mch_code ,mch_level ) values ('1','machine1',null,'level1'); 
 insert into machine_mast(mch_code,mch_name,parent_mch_code ,mch_level ) values ('11','machine2','1','level11'); 
 insert into machine_mast(mch_code,mch_name,parent_mch_code ,mch_level ) values ('111','machine3','11','level111'); 

--i need a select statement if i pass mch_code = '111' 
it must return '11'

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