Trip Expense Types based upon Trip Activity Type

Hi

I have a requirement. I know that Travel Expense Types do have the permissibility based upon "Employee Grouping for Travel Expense Types". This is being done in V_T706B1 in the field 'ExpTy.Permissibility'. Based upon the group the employee belongs to, he/she can have the visibility to the expense type in 'Travel Expense Report'

Now my requirement is can I have the same type of permissibility to travel expense types based upon the Trip Activity type. For example if I choose a trip activity type 'Billable to Customer' in Trvael Request Form I should be able to see expense types AIR, TRAIN while if I choose 'Internal Training' I should be able to see only TRAIN in Travel Expense Report.

Is this possible?