I asked the same question in the Security forum, but since no respond did I get, I'm posting it here either.
I read that Libnftnl is a userspace library providing a low-level netlink programming interface to the in-kernel nf_tables subsystem and it uses NFTables.
[UPDATE] : NFTables is used for in-kernel packet classification.
Since it's a kernel related topic, at the very first time of hearing it the only thing sprang to my mind was SELinux whilst we can use it to manage our networking security solutions such as Labeled Networking (Labeling Packets passing between machines over the Network) amongst all other options it provides.
So is it something like what we can do via SELinux or not? If not so, does anyone know why we may be in need of using NFTables and Libnftnl? Do we need it at all?