gistfile1.txt

var predicate = PredicateBuilder.True<Person>();
if (filderOptions.FirstName != null)
    predicate = predicate.AndAlso(p=>p.FirstName == "Alex");

if (filderOptions.SomeNullable.HasValue)
    predicate = predicate.AndAlso(p=>p.SomeProp == filterOptions.SomeNullable.Value);

var where = queryable.Where(predicate);

// will create an expresion which looks like this: p => true && p.FirstName == "Alex" && p.SomeProp == filterOptions.SomeNullable.Value)