When trading with the netting account model, you can only have one open position in the same instrument. Therefore:
When trading with the hedging account model, you can open as many positions as you want in the same instrument in different directions, in case there is enough margin for opening and maintaining them.
If you already have an open order in some instrument and you decide to open another one, you will have one more open position. Unlike the netting model, in the hedging model opening a new position in an instrument has no influence on existing ones.