Coapp / autopkg : multiple include folders in /build/native/include/

I am trying to build a nuget package via CoApp tool for c++. The package needs to embed 3 folders when compiling a cpp using it.

So, I want an internal include structure as following :

/build/native/include/lib1, /build/native/include/lib2, /build/native/include/lib3

My question: how to add several include folders in /build/native/include/

I tryied :

Multiple blocs of (varying lib1, lib2, lib3):

    nestedInclude += 
    { 
        #destination = ${d_include}lib1; 
        ".\lib1\**\*.hpp", ".\lib1\**\*.h"
    };

Multiple blocs of (varying lib1, lib2, lib3):

    nestedInclude 
    { 
        #destination = ${d_include}lib1; 
        ".\lib1\**\*.hpp", ".\lib1\**\*.h"
    };

but it seems coapp accumulates the .h/.hpp files among the blocs (depending of operator += or not) and at the end, add all of them to the last #destination tag value. So I get an unique entry : /build/native/include/lib3