How can a Bitcoin transaction be used multiple times (If it is so)? My understanding is that a transaction is a transfer of value between Bitcoin wallets that gets later included in the block chain. So a Bitcoin transaction is used only once in my understanding.
What is spent it's not the transaction itself, but the outputs the transaction has created. A transaction can have multiple outputs with different bitcoin amount hold on each one. 

Therefore, a transaction can be "used", in the sense you expressed it, as many times as outputs it has.