I don't think you need the first predicate you create. Wont this return the results you need?
var classFilter = PredicateBuilder.False<ListRecord>();
classFilter = classFilter.Or(x => x.Community == "Air Force");
classFilter = classFilter.Or(x => x.Community == "Navy");
// Add several more predicates just like classFlter
var query = db.ListRecords.AsExpandable().Where(classFilter);
var list = query.ToList();
Or with additional predicates like Classfilter:
var classFilter = PredicateBuilder.False<ListRecord>();
classFilter = classFilter.Or(x => x.Community == "Air Force");
classFilter = classFilter.Or(x => x.Community == "Navy");
var list = db.ListRecords.AsExpandable()
.Where(classFilter)
.Where(someOtherFilterLikeClassFilter)
.Where(AnotherOneLikeClassFilter)
.ToList();