I do not know what exactly you want to achieve. But most probably your problem can be solved using combination of iproute2 utilities and iptables.
In this you create additional routing tables. These are added in /etc/iproute2/rt_tables
And then you set up the routing rules to choose what routing table to route with.
You can mark specific packet using iptables using -j MARK –set-mark 1 and then again using iproute2 utilities you can use a particular routing table ip rule add fwmark 1 table 1.
"advanced routing" might be the keywords.
The link you mentioned says
Whenever possible, you should use the MARK target together with
iproute2 instead of this ROUTE target. However, this target is useful
to force the use of an interface or a next hop and to change the
incoming interface of a packet. People also use it for easiness and to
simplify their rules (one rule to route a packet is easier that one
MARK rule + one iproute2 rule).
you may look at