For multicurrency transactions, PayPal will give a corresponding currency conversion feed. You must exclude the feeds corresponding to the foreign currency amount, and categorize the feeds in base currency alone.
For example, if your base currency is HKD and, when a 100 USD deposit is made, PayPal will give the following feeds:
Here, you can exclude the two 100 USD feeds and categorize the 775.314 HKD feed.
These USD transactions will not be displayed in USD. However, you can identify a deposit and withdrawal of the same amount on the same day and exclude them.
and GST filing.