Categorization in Sales Contract

Hi Expert,

I have a requirement to show categorization at header and item level of sales contract , I did below things to achive this  :

At Header level :

1 . Created a component usage of BTCategory component and used View CUBTCategories.BTCATEGORIES/OVEWindow.

2 . Assigned it to ViewSet BT121H_SLSC/ContractOP .

3 .Cretaed a  Custom controller ZBT121H_SLSC/CUBTCategoriesCuCo and created two contaxt node (below screen )

4 . I redifined the WD_USAGE_INITIALIZE of component controller :

5 . When I go to web ui for sales contract for particular transaction type .I can see my category view but drop down is disable :

My question is why the drop down is disable , please help me to make these enable .

At Item leavel :

I have done same things as I did for Header , except in custom controller I used BTADMINI bol model . But in item leave drop down is hidden :

Second uestion is why drop down is hidden ?

Please help ?

Thanks & Regards,

Akhilesh Bhagat.