Hello.
Is there any way (except using separated accounts) to enter an order without it being interrupted by other orders next to it?
I mean, is there any way to create separated layer for each order on the same strategy?
Thanks!

What do you mean by interfering orders? If you want to have both open long and short positions on the same instrument your only option with NT is having separate strategies/(sub)accounts.
If you only want to have different long positions at the same time, you provide signal name to EnterLong then you can have full control over the order especially if you use IOrders to manage them.