How to set the loan limits and sublimits

Hi,

Can you guide me to set the loans (Facilities) limits and sub limits in treasury management?

My company having 2 billion borrowing limit with bank and again divided 60% under Tranche-A and 40% under Tranche-B as sub limits. If i borrow money from the bank, it will issue under both sub limits. Only interest rates are different for sub limits. System should check these limits at the time of facilities creation for this partner. Please guide me to acheive this functionality in SAP TRM.

Regards,

ANJIREDDY