[Mathias.]

Is there a way to tell the compiler to use multiple include path?

[Maxximou5]

Note: When compiling preexisting plugins it is easiest to move the included from the plugin source folder to the include folder in your sourcemod/scripting/include. Please see Spcomp_switches specifically the -i parameter for specifying a different folder for includes.

https://wiki.alliedmods.net/Compiling_SourceMod_Plugins
Here's the list: https://wiki.alliedmods.net/Spcomp_switches
Not sure about multiple, but give it a try, with -i.