Tiered Affiliate Rates — Per-Group Tier Structures

add_filter( 'affwp_get_affiliate_rate', function( $rate, $affiliate_id, $type ) {

    // Respect individual rates -- if the affiliate has one set manually, skip group tiers.

    $affiliate_rate = affiliate_wp()->affiliates->get_column( 'rate', $affiliate_id );

    if ( ! empty( $affiliate_rate ) ) {

        return $rate;

    }

    // Get the affiliate's group ID.

    try {

        $group_id = affwp_get_affiliate_group_id( intval( $affiliate_id ) );

    } catch ( Exception $e ) {

        return $rate;

    }

    if ( ! $group_id ) {

        return $rate;

    }

    // ---------------------------------------------------------------

    // Define group-specific tier structures.

    //

    // Replace the array keys (10, 11) with your actual group IDs.

    // Find the ID by going to AffiliateWP > Groups, clicking a group

    // to edit, and reading the ?id= value in the URL.

    //

    // Each tier:

    //   'type'      => 'referrals' or 'earnings'

    //   'threshold' => minimum count or dollar amount to reach this tier

    //   'rate'      => commission percentage as a whole number (20 = 20%)

    //

    // List tiers from lowest to highest -- the snippet picks the highest met.

    // ---------------------------------------------------------------

    $group_tiers = array(

        // Group A (e.g. "Silver") -- replace 10 with actual group ID

        10 => array(

            array( 'type' => 'referrals', 'threshold' => 10, 'rate' => 10 ),

            array( 'type' => 'referrals', 'threshold' => 25, 'rate' => 15 ),

            array( 'type' => 'referrals', 'threshold' => 50, 'rate' => 20 ),

        ),

        // Group B (e.g. "Gold") -- replace 11 with actual group ID

        11 => array(

            array( 'type' => 'referrals', 'threshold' => 5,  'rate' => 15 ),

            array( 'type' => 'referrals', 'threshold' => 20, 'rate' => 20 ),

            array( 'type' => 'referrals', 'threshold' => 40, 'rate' => 25 ),

        ),

    );

    if ( ! isset( $group_tiers[ $group_id ] ) ) {

        return $rate;

    }

    $tiers_expire = null !== affiliate_wp()->settings->get( 'rate-expiration', null );

    if ( $tiers_expire ) {

        $start     = date( 'Y-m-d H:i:s', strtotime( 'first day of', current_time( 'timestamp' ) ) );

        $end       = date( 'Y-m-d H:i:s', current_time( 'timestamp' ) );

        $earnings  = affiliate_wp()->referrals->paid_earnings( 'month', $affiliate_id, false );

        $referrals = affiliate_wp()->referrals->count( array(

            'affiliate_id' => absint( $affiliate_id ),

            'status'       => 'paid',

            'date'         => array( 'start' => $start, 'end' => $end ),

        ) );

    } else {

        $earnings  = affwp_get_affiliate_earnings( $affiliate_id, false );

        $referrals = affwp_get_affiliate_referral_count( $affiliate_id );

    }

    foreach ( array_reverse( $group_tiers[ $group_id ] ) as $tier ) {

        if ( empty( $tier['threshold'] ) || empty( $tier['rate'] ) ) {

            continue;

        }

        $threshold_met = ( 'earnings' === $tier['type'] )

            ? $earnings  >= affwp_sanitize_amount( $tier['threshold'] )

            : $referrals >= intval( $tier['threshold'] );

        if ( $threshold_met ) {

            return 'percentage' === $type ? $tier['rate'] / 100 : $tier['rate'];

        }

    }

    return $rate;

}, 11, 3 );