scoping

var self = this;
$.each(this.filters, function(index, filter) {
    filter.label = (self.labels[filter.field] && self.labels[filter.field][filter.value]) ?
        self.labels[filter.field][filter.value] :
        filter.value;

    AjaxSolr.theme(
        'activeFilterListItem',
        filter,
        function() {
            self.removeFilter.call(self, filter);
        }
    ).appendTo(list);
});