<?php
/**
 * Get Field Options
 */
function yzc_get_xprofile_field_options( $field_id ) {

    // Get Field Data.
    $field = new BP_XProfile_Field( $field_id );

    // Get Select Box Options.
    $children = $field->get_children();

    //
    $options = wp_list_pluck( $children, 'name' );

    return $options;
}

/**
 * Add New Xprofile Field As new Filter.
 */
function yzc_add_new_members_directory_filter() {

    // Get Field ID.
    $field_id = 625;

    // Get Field Options.
    $options = yzc_get_xprofile_field_options( $field_id );

    ?>

    <li id="members-city-select" class="last filter">
        <select id="members-city-by">
            <option value=""><?php _e( 'Filter By City', 'youzer' );?></option>
            <?php foreach ( $options as $option ) : ?>
                <option value="<?php echo $option; ?>"><?php echo $option; ?></option>
            <?php endforeach; ?>
        </select>
    </li>

    <?php
}

add_action( 'bp_members_directory_member_sub_types', 'yzc_add_new_members_directory_filter' );


/**
 * Members Directory - Set Field Filter.
 */
function yzc_set_filter_by_xprofile_field( $loop ) {

    // Get Field ID.
    $field_id = 625;

    // Get Field Options.
    $options = yzc_get_xprofile_field_options( $field_id );

    if ( bp_is_members_directory() && isset( $_POST['filter'] ) && in_array( $_POST['filter'], $options ) ) {
        $loop['type'] = 'alphabetical';
        $loop['search_terms'] = $_POST['filter'];
    }

    return $loop;

}

add_filter( 'bp_after_has_members_parse_args', 'yzc_set_filter_by_xprofile_field', 9999 );