How to put the .h file in modulemap file properly?

I have the native static lib that has a few .h files as API, the dir structure looks like this

3rdParties -
            - MyAPIHeader.h
            - my.modulemap 

my modulemap file looks like this

module MyAPIHeader {
 header "MyAPIHeader.h"
 export *
}

and everything works well, up until I need to add another API file to my modulemap structure that does not reside in the same dir.

anotherProjectDir -
                  - AnotherAPIHeader.h

3rdParties -
            - MyAPIHeader.h
            - my.modulemap 

and my modulemap file looks like this

module MyAPIHeader {
 header "MyAPIHeader.h"
 export *
}

module AnotherAPIHeader {
 header "AnotherAPIHeader.h"
 export *
}

and then when I try to use AnotherAPIHeader functions I got such an error in the modulemap file

Header 'AnotherAPIHeader.h' not found

I tried to set the path to the .h file in the module map as relative (not works) then I tried to set the path to the header file in the target (not works).

To sum up - when the .h file that is included in the module map resides in the same dir as a module map it works, when .h file resides in the other dir there is no way to set relative dir to that .h file.

What am I missing?