SLA Source for Payables Tax BSV

Hi,

My client requirment is to have the Tax BSV same as Liability and Expense for all invoice distributions.

Eg: if the expense BSV and Liablity BSV are A , tax BSV also should be A. If they are B ,then tax BSV also should be B.

i  created diff ADRs  and selected the source as Invoice distribution account ,invoice liability acct and tried to change the BSV values by asigning this ADR to Recoverable tax line in Invoice journal Description.

But still the tax BSV is coming as C which is defined in the Recoverable rate in E-tax.

Please let me knwo which source and how the ADR need to be developed based on the source to satisfy the requirement?