SLA Change for Tax Rate Variance account code combination based on PO Line Item Type (Inventory Or E

Dear Experts,

Business doesn't have any tax amount in PO but in invoice they have tax amount. Receipt is also accrued. created matched invoice,  it hits tax rate variance in the invoice distribution level. Business requirement is Tax Rate Variance account Code combination based on PO Line Item Type (Inventory Or Expense), If PO line item is inventory item Department segment values default to 0000 and for expense item no need any change in account code combination. Could please guide how to create a SLA rule for this business requirement?

Thank,

Vikram