How to Write Account Rule for Exchange Gain/Loss

Hello Experts,

We have a requirement stating that in receipt accounting, especially for Invoice price adjustment transaction type.

Business is expecting the accounting similar to common options payables,

At invoice level, system is picking the combination from common options payables

Exchange Gain - Credit

Exchange Loss - Debit 

At receipt Accounting Level.

Exchange Gain - Debit 

Exchange Loss - Credit

Based on the above entries, business is expecting to map the respective Gain/ Loss accounts:

Possibilities Tried:

1. Account Rule:
   1. Condition under Gain Mapping Set
      1. "Line Type"(PSX,S,S) = DEBIT 'And' "Accounting Line Type"(CMR,S,S) = EXCHANGE_VARIANCE_ADJUSTMENT