Subdomains Permalink

Hi every one! I’ve been wordking with wordpress and Modernize theme for get one web with 3 subdomains where the content is always the same but Logos/Menu changes depending on subdomain. Until now i’ve editing the theme code, but for this i don’t find solution.
Multisites in wordpress are NOT my solutions because duplicates content.

Now i’ve a problem getting permalinks for portfolio items. This is what happend:

If i am on http://livingvalencia.reservatuapartamento.com/andorra/ and press on one of the items it redirects to the main domain (http://www.reservatuapartamento.com/apartamentos/cimpas/).
Check that domain has changed. This is because there is a get_permalink function in theme for this.

So, how can i change permalink depending on subdomain where i am? I think i need to edit get_permalink function.

Thanks