If I bet on a selection on the Sportsbook and lay the same selection on the Exchange, is this treated in the same way as backing and laying on the Exchange or is it treated as two separate bets?

No, it is not the same as backing and laying the same selection on the Exchange.

It is in fact treated as 2 separate bets, therefore if you place a bet on a selection on the Sportsbook and lay the same selection on the Exchange you will need to have the necessary funds available in your balance to cover both bets independently. Our Sportsbook and Exchange products are independent from each other.