New Category Sets not visible in Purchase Order

Hi

we are in 12.1.3. Currently one Category set  ( Say A)  has been assigned as  a Default Category set for Functional Area 'Purchasing'  and  Categories under that Category Set  is  available under   Purchase Order> Lines>Categories. Same behaviour in  Purchase requisitions as well. This Category set  has been defined with single Segment.

Now  the requirement  is to have  New Category Set  (Say   with two Segments   and the  Categories under this New set would be used for Ordering Non Inventory Catagories. Post defining New Category Set and assingning with Categories, expectation is have these new Categories  listed in Purchase Order and Purchase  reqs. But these Categories under new Category set (B) is not visible in Purchase Order Lines >Categories LOV and Only  Categories associated with  Category Set A ( Default Category Set for Purchasing) is Visible.Can you please suggest a way to fix this.