BOM Query with Parent and child

Hi All,

I'm looking for a BOM query which gives me Parent and Child details. I have below one but what i need is differently to display last child also in parent which no component next to it.

For example :

Parent

Level 1 Chiild - child2

Level 2 Child2 - Child3

I'm expecting an output like this

Parent

Level 1 Chiild - child2

Level 2 Child2 - Child3

Level 3/NA Child3 - -

Pls help on this one as CONNECT BY PRIOR didnt help me to get in above format. Sample Query is attached here.

SELECT  LPAD (' ', LEVEL * 2) || LEVEL order_level,

msib.segment1 parent,