Modify travel request screens in TRIP transaction

We want to use the travel request only to request advances and nothing else. Hence we would want to remove all the other options in the travel request section of trip transaction. Effectively there should be only general trip information and advances section in the travel request.

Where do i configure this. Under travel eruest section of travel management, I do not see anything like dialog control that we have for travel expenses.

I do not see any BADI's to get the same.

Any inputs on how to do this?