How to add Business unit drop down list condition in LedgerJournalTransDimension Form

Dear All,

In form GL>>General Journal >> new >> GJV>>lines >>account type ="Vendor">> Financial Dimensions >> Business Unit Drop Down.

As my vendor does not have Business Unit defined while creation, and it cannot be done logically, Business unit should selected from drop down which shows all Bu's Globally of all companies. Is there a way to reduce drop down values to if ( Current Company = "XYZ" then BU like '001* .assume company XYZ has BU's 0011,0012,0013.