Adds profile permissions to view/edit.

functions.php

function um_custom_can_view_profile( $can_view, $user_id ) {
	if ( ! is_user_logged_in() ) {
		if ( user_can( $user_id, 'um_volunteer' ) ) {
			$can_view = false;
		}
	} else {
		if ( current_user_can( 'um_volunteer' ) && user_can( $user_id, 'um_volunteer' ) ) {
			$can_view = false;
		}
	}
	return $can_view;
}
add_filter( 'um_can_view_profile', 'um_custom_can_view_profile', 10, 2 );

function um_custom_pre_profile_shortcode() {
	add_filter( 'um_redirect_home_custom_url', 'um_custom_redirect_home_custom_url', 10, 3 );
}
add_action( 'um_pre_profile_shortcode', 'um_custom_pre_profile_shortcode', 9 );

function um_custom_redirect_home_custom_url( $url, $requested_user_id, $is_my_profile ) {
	if ( ! $is_my_profile ) {
		if ( ! is_user_logged_in() ) {
			if ( user_can( $requested_user_id, 'um_volunteer' ) ) {
				$url = 'redirect_url_with_notice;
			}
		} else {
			if ( current_user_can( 'um_volunteer' ) && user_can( $requested_user_id, 'um_volunteer' ) ) {
				$url = 'redirect_url_with_notice;
			}
		}
	}
	return $url;
}