Edit in JSFiddle

var options = {
    valueNames: ["name", "town", "cuisine", "description"],
    item: '<li class="restaurant-item"><div class="restaurant-container"><div class="restaurant-info"><h3 class="name"></h3><div class="town"></div><div class="cuisine"></div><summary class="description"></summary></div><a target="_blank" class="url"><button class="more-info">more info</button></a><div class="clear"></div></div></li>'
};

var values = [{
    name: "Aki Japanese Restaurant",
    town: "Bloomfield",
    cuisine: "Japanese",
    description: "A sleek and stylish restaurant that offers healthy and flavorful food that is served fresh.",
    url: "http://www.akisushius.com/"
}, {
    name: "Cloverleaf",
    town: "Caldwell",
    cuisine: "Bar/Pub",
    description: "Offering a menu consisting of American cuisine in a family-casual dining atmosphere.",
    url: "http://www.cloverleaftavern.com/"
}, {
    name: "LuNello",
    town: "Cedar Grove",
    cuisine: "Italian",
    description: "Offers a classic Italian menu with special homemade and signature dishes that exude quality.",
    url: "http://www.lunello.com/"
}, {
    name: "Calandra's Mediterranean Grill",
    town: "Fairfield",
    cuisine: "Mediterranean",
    description: "A family friendly restaurant featuring an open kitchen with a wood burning grill and stone pizza oven.",
    url: "http://www.calandrasmedgrill.com/home.html"
}, {
    name: "Stamna Greek Taverna",
    town: "Little Falls",
    cuisine: "Greek",
    description: "Enjoy home cooked traditional Greek fare with ambiance that portraits the feel of Greece.",
    url: "http://www.stamnataverna.com/"
}, {
    name: "Strip House",
    town: "Livingston",
    cuisine: "Steakhouse",
    description: "Serving cuts of meat primed to perfection, an extensive wine list, and their famed 24-layer chocolate cake.",
    url: "http://www.striphousenewjersey.com/"
}, {
    name: "Fricasse French Bistro",
    town: "Montclair",
    cuisine: "French",
    description: "Specializing in high quality daily specials and fine French cuisine served in a bistro setting.",
    url: "http://www.fricasseebistro.com/"
}, {
    name: "Samurai Sushi",
    town: "Livingston",
    cuisine: "Japanese",
    description: "A relaxing ambiance combining the Zen-like calm of a Japanese garden with a modern, NY sushi bar style.",
    url: "http://www.usasamurai.com/"
}];

var restaurantList = window.restaurantList = new List('restaurant-list', options, values);

function filterByValues(filterItems) {
    //this really needs to be refactored
    filterItems.towns = filterItems.towns === null ? [] : filterItems.towns;
    filterItems.cuisines = filterItems.cuisines === null ? [] : filterItems.cuisines;
    if (filterItems.towns.length === 0 && filterItems.cuisines.length === 0) {
        restaurantList.filter();
    } else if (filterItems.towns.length > 0 && filterItems.cuisines.length === 0) {
        restaurantList.filter(function (item) {
            var values = item.values();
            for (var i in filterItems.towns) {
                if (values.town === filterItems.towns[i]) {
                    return true;
                }
            }
            return false;
        });
    } else if (filterItems.cuisines.length > 0 && filterItems.towns.length === 0) {
        restaurantList.filter(function (item) {
            var values = item.values();
            for (var i in filterItems.cuisines) {
                if (values.cuisine === filterItems.cuisines[i]) {
                    return true;
                }
            }
            return false;
        });
    } else {
        restaurantList.filter(function (item) {
            var values = item.values();
            for (var town in filterItems.towns) {
                for (var cuisine in filterItems.cuisines) {
                    //TODO I need to think about how to best filter by the union of the two
                    if (values.town === filterItems.towns[town] && values.cuisine === filterItems.cuisines[cuisine]) {
                        return true;
                    }
                }
            }
            return false;
        });
    }
}

var selected = {
    towns: [],
    cuisines: []
};

function townUpdate(e, obj) {
    if (obj === undefined) {
        selected.towns = $(e.target).val();
        filterByValues(selected);
    } else if (obj.selected !== undefined) {
        selected.towns.push(obj.selected);
        filterByValues(selected);
    } else if (obj.deselected !== undefined) {
        selected.towns = _.without(selected.towns, obj.deselected);
        filterByValues(selected);
    }
}

function cuisineUpdate(e, obj) {
    if (obj === undefined) {
        selected.cuisines = $(e.target).val();
        filterByValues(selected);
    } else if (obj.selected !== undefined) {
        selected.cuisines.push(obj.selected);
        filterByValues(selected);
    } else if (obj.deselected !== undefined) {
        selected.cuisines = _.without(selected.cuisines, obj.deselected);
        filterByValues(selected);
    }
}

$(".chosen-select.cuisines").on("chosen:ready", function (e, obj) {
    this.removeChild(this.firstElementChild);
}).chosen({
    display_disabled_options: false
}).change(cuisineUpdate).trigger("chosen:updated");
$(".chosen-select.towns").on("chosen:ready", function (e, obj) {
    this.removeChild(this.firstElementChild);
}).chosen({
    display_disabled_options: false
}).change(townUpdate).trigger("chosen:updated");

// Some underscore methods to make my life easier
var ArrayProto = Array.prototype,
    concat = ArrayProto.concat,
    slice = ArrayProto.slice,
    each = ArrayProto.each,
    nativeFilter = ArrayProto.filter,
    nativeIndexOf = ArrayProto.indexOf,
    _ = {};

_.without = function (array) {
    return _.difference(array, slice.call(arguments, 1));
};

_.difference = function (array) {
    var rest = concat.apply(ArrayProto, slice.call(arguments, 1));
    return _.filter(array, function (value) {
        return !_.contains(rest, value);
    });
};

_.filter = function (obj, iterator, context) {
    var results = [];
    if (obj == null) return results;
    if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
    each(obj, function (value, index, list) {
        if (iterator.call(context, value, index, list)) results.push(value);
    });
    return results;
};

_.contains = function (obj, target) {
    if (obj == null) return false;
    if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1;
    return any(obj, function (value) {
        return value === target;
    });
};

<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<div class="container">
    <select data-placeholder="Choose a town..." multiple class="chosen-select towns">
        <option value='' disabled selected style='display:none;'>Choose a town...</option>
        <option>Belleville</option>
        <option>Bloomfield</option>
        <optgroup label="The Caldwells">
            <option>Caldwell</option>
            <option>North Caldwell</option>
            <option>West Caldwell</option>
        </optgroup>
        <option>Cedar Grove</option>
        <option>Essex Fells</option>
        <option>Fairfield</option>
        <option>Glen Ridge</option>
        <option>Irvington</option>
        <option>Livingston</option>
        <option>Maplewood</option>
        <option>Millburn</option>
        <option>Montclair</option>
        <option>Newark</option>
        <option>Nutley</option>
        <optgroup label="The Oranges">
            <option>East Orange</option>
            <option>Orange</option>
            <option>West Orange</option>
            <option>South Orange</option>
        </optgroup>
        <option>Roseland</option>
        <option>Verona</option>
    </select>
    <select data-placeholder="Choose a cuisine..." multiple class="chosen-select cuisines">
        <option value='' disabled selected style='display:none;'>Choose a cuisine...</option>
        <option>Japanese</option>
        <option>Bar/Pub</option>
        <option>Italian</option>
        <option>Mediterranean</option>
        <option>Greek</option>
        <option>Steakhouse</option>
        <option>French</option>
    </select>
    <div id="restaurant-list">
        <ul class="list"></ul>
    </div>
</div>

body {
    margin: 10px;
    font-family: sans-serif;
    background-color: white;
    font-size: 18px;
    min-width: 320px;
}
.container {
    position: relative;
    width: 590px;
    width: 33em;
    margin: 0 auto;
}
.chosen-select, .chosen-container {
    width: 49.5% !important;
}
/*
#restaurant-list {
    width: 590px;
    width: 33em;
}
*/
 .name {
    margin: 0.2em 0;
    color: #007dc5;
    font-weight: 300;
}
.clear {
    clear: both;
}
.restaurant-item {
    padding: 0.35em 1em 0.65em;
    margin: 1em 0;
    list-style: none;
    background-color: #e6e7e8;
    color: #231f20;
    font-weight: 100;
}
.list {
    padding-left: 0;
}
.restaurant-info {
    float: left;
    width: 75%;
}
.more-info {
    font-size: 24px;
    font-weight: 600;
    text-align: center;
    margin-top: 4px;
    width: 4.1em;
    float: right;
    border: 0;
    line-height: normal;
    padding: 9px 14px 9px;
    /* This seems to be jittery when the page reflows */
    padding: 0.375em 0.583em;
    -webkit-border-radius: 6px;
    -moz-border-radius: 6px;
    border-radius: 6px;
    background-color: hsl(201, 100%, 30%) !important;
    background-repeat: repeat-x;
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr="#00a5ff", endColorstr="#006399");
    background-image: -khtml-gradient(linear, left top, left bottom, from(#00a5ff), to(#006399));
    background-image: -moz-linear-gradient(top, #00a5ff, #006399);
    background-image: -ms-linear-gradient(top, #00a5ff, #006399);
    background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #00a5ff), color-stop(100%, #006399));
    background-image: -webkit-linear-gradient(top, #00a5ff, #006399);
    background-image: -o-linear-gradient(top, #00a5ff, #006399);
    background-image: linear-gradient(#00a5ff, #006399);
    border-color: #006399 #006399 hsl(201, 100%, 25%);
    color: #fff !important;
    text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.33);
    -webkit-font-smoothing: antialiased;
}
@media only screen and (max-width : 620px) {
    .container {
        width: 98%;
        font-size: 15px;
    }
    .more-info {
        font-size: 18px;
    }
    .chosen-select, .chosen-container {
        width: 49.4% !important;
    }
}
@media only screen and (max-width : 365px) {
    .more-info {
        font-size: 16px;
        width: 4.1em;
        padding: 0.5em 0.6em;
    }
    .chosen-select, .chosen-container {
        width: 49.3% !important;
    }
}