srkileee

Yes, that is what I was trying to connect.
1. post type is projekat
2. post type is project

Is there a way to connect them or it only works if the post types on both sites are the same?

I am hoping that they will give you some idea what is my problem

function my_msls_options_get_permalink( $url, $language ) {
    if ( 'sr_RS' == $language ) {
        $url = str_replace( '/project/', '/projekat/', $url );
        $url = str_replace( '/project-category/', '/kategorija-projekta/', $url );
    }
    elseif ( 'us' == $language ) {
        $url = str_replace( '/projekat/', '/project/', $url );
        $url = str_replace( '/kategorija-projekta/', '/project-category/', $url );
    }
    return $url;
}
add_filter( 'msls_options_get_permalink', 'my_msls_options_get_permalink', 10, 2 );

Nothing

When I go to link the translation, link points me to:
From Serbian to English
http://en.enterijeriluster.com/wp-admin/post-new.php?post_type=projekat
From English to Serbian
http://enterijeriluster.com/wp-admin/post-new.php?post_type=project

Should be:

From Serbian to English
http://en.enterijeriluster.com/wp-admin/post-new.php?post_type=project
From English to Serbian
http://enterijeriluster.com/wp-admin/post-new.php?post_type=projekat

Here is example of links I want to connect
http://enterijeriluster.com/projekat/eksterijer/
http://en.enterijeriluster.com/project/exterior/