Link Profile Field to Member Type.

yzc_link_profile_field_to_member_type.php

<?php

/**
 * Link Profile field to member type.
 */
function yzc_link_profile_field_to_member_type( $data_field ) {

    // Check if field type is member types. 
    if ( 3 != $data_field->field_id ) {
        return ;
    }

    // Get User ID.
    $user_id = $data_field->user_id;
    
    if ( empty( $data_field->value ) ) {
        // Remove Member Type.
        bp_set_member_type( $user_id, '' );
        return;
    }

    switch ( $data_field->value ) {

        case 'Human':
        
            if ( bp_get_member_type_object( 'guardian' ) ) {
                bp_set_member_type( $user_id, 'guardian' );
            }
        
            break;
        
        case 'Company':
        
            if ( bp_get_member_type_object( 'company' ) ) {
                bp_set_member_type( $user_id, 'company' );
            }
            break;

        case 'School':
        
            if ( bp_get_member_type_object( 'school' ) ) {
                bp_set_member_type( $user_id, 'school' );
            }
            break;

        case 'NonProfit':
            
            if ( bp_get_member_type_object( 'nonprofit' ) ) {
                bp_set_member_type( $user_id, 'nonprofit' );
            }

            break;

    }
}

add_action( 'xprofile_data_after_save', 'yzc_link_profile_field_to_member_type' );