Remove lihtium search interface, only search in the area or in or members

Marianne80 - 

Do you want to show only search member option and hide all others options?  If you are showing only one option(search member), I believe there is no need to show drop-down either. 

This can be achieved using jQuery.  

jQuery(".lia-search-form-granularity").find('[value!="user|user"]').wrap('<span>'); 

The above code will hide all other option in search drop-down for all the users including admin, moderator,  etc. You can restrict it by checking the logged in user role.