var predicateown = PredicateBuilder.True<Owners>();
            
           foreach (OwnersObject ow in ListFindOwn)
            {
                var predicateownsel = PredicateBuilder.True<Owners>();

                if (ow.fmown != null) if (ow.fmown.Trim().Length != 0)
                        predicateownsel = predicateownsel.And(x => SqlMethods.Like(x.FmOwn, String.Format("{0}%", ow.fmown)));
                
                if (ow.nmown != null) if (ow.nmown.Trim().Length != 0)
                        predicateownsel = predicateownsel.And(x => SqlMethods.Like(x.NmOwn, String.Format("{0}%", ow.nmown)));

                predicateown = predicateownsel.Or(predicateown);
            }

            var q_own = own_data
                .Where(predicateown)
                .Select(x => x).ToList();

where FmOwn like 'иванов%' and nmown 'иван%' or FmOwn like 'Петров%'