<input name="Income" /> <div mvc-lookup-for="Id" url="People" filters="Income"></div>

public class HomeController : Controller
{
    private DbContext Context { get; }

    public HomeController(DbContext context)
    {
        Context = context;
    }

    [HttpGet]
    public JsonResult People(LookupFilter filter, Int32? income)
    {
        // Model property names are filtered automatically for not null values.
        filter.AdditionalFilters[nameof(Person.Income)] = income;

        // Custom names should be filtered by overriding `FilterByAdditionalFilters` method.
        filter.AdditionalFilters["IsWorking"] = true;

        return Json(new PeopleLookup(Context) { Filter = filter }.GetData());
    }
}

public class PeopleLookup : ALookup<Person>
{
    private DbContext Context { get; }

    public PeopleLookup(DbContext context)
    {
        Context = context;
        FilterCase = LookupFilterCase.Lower;
    }

    public override IQueryable<Person> GetModels()
    {
        return Context.Set<Person>();
    }

    public override IQueryable<Person> FilterByAdditionalFilters(IQueryable<Person> models)
    {
        if (Filter.AdditionalFilters.ContainsKey("IsWorking") && (Boolean?)Filter.AdditionalFilters["IsWorking"] == true)
            models = models.Where(model => model.Income > 0);

        return base.FilterByAdditionalFilters(models);
    }
}