Check member promise chaining psuedo

$.ajax({
    // Get communities' URL
})
    .then(function (communities) {
        var promises;
        for (var i = 0; i < communities.length; i++) {
            promises.push($.ajax({
                // Get groups with matching title for matching user on community URL
            }));
        }
        return $.when.apply(this, promises);
    })
        .then(function (communityMemberships) {
            var communitiesToAdd = communityMemberships.filter(isMember);
            // Code to perform on communities where user is not a member
        });

var isMember = function (membership) {
    return membership == 0;
}