I think a little bit more information is needed in order to find an adequate supervisor in your field..., like some more information on your specific topic of research. Also, I would suggest you ask your supervisor if they have any particular expert on mind, or you could also look for researchers on Scopus or Google Scholar who are working in your area, and try to contact them with a co-supervision suggestion.

Jelena Marinkov Hello, thanks so much for your advice I will do that, but I'm looking for a co-supervisor urgently...

Search on Linkedin.