string filter="alex, faheem, Cohen";
var filterArr=filter.Split(new []{','},StringSplitOptions.RemoveEmptyEntries).Select(f=>f.Trim()).ToList();

var users= (from u in DbContext.Users
                where filterArr.Any(y=> u.Name.Contains(y)) select u);

string filter = "alex, faheem, Cohen";
var filterArr = filter.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(f => f.Trim()).ToList();
var users = _dbContext.Users.Where(x => filterArr.Any(n => n.Contains(x.Name))).ToList();