Yes it is possible to use LDAP authentication in multiple domains in 1 forest
Then you need to authenticate users base for the different port in source.
Like some user will put 8080 in browser to authenticate with Auth1, while some users will use 9090 port for auth2.
Then you can create policy as required
Could you help to explain in detail of this solution for make me more understand.
i will use your solution to test in my Lab.