Add meta user fields via Metabox.io so that Oxygen Builder can pull the field data.

oxygen_user_meta.php

<?php
/**
 * Add the fields via Metabox.io
**/
function stoute_user_register_meta_boxes( $meta_boxes ) {
	$prefix = 'social_';

	$meta_boxes[] = [
		'title'   => esc_html__( 'Social Media', 'stoute_users' ),
		'id'      => 'social',
		'type'		=> 'user',
		'fields'  => [
			[
				'type' => 'url',
				'name' => esc_html__( 'Facebook', 'stoute_users' ),
				'id'   => $prefix . 'facebook',
			],
			[
				'type' => 'url',
				'name' => esc_html__( 'Instagram', 'stoute_users' ),
				'id'   => $prefix . 'instagram',
			],
			[
				'type' => 'url',
				'name' => esc_html__( 'LinkedIn', 'stoute_users' ),
				'id'   => $prefix . 'linkedin',
			],
			[
				'type' => 'url',
				'name' => esc_html__( 'YouTube', 'stoute_users' ),
				'id'   => $prefix . 'youtube',
			],
		],
	];

	return $meta_boxes;
}
add_filter( 'rwmb_meta_boxes', 'stoute_user_register_meta_boxes' );

/**
 * Add functions to have Oxygen pull the meta data
**/

function get_author_facebook() {
	$author_id = get_the_author_meta( 'ID' );
	$facebook_url = get_field('social_facebook', 'user_' . $author_id);
	return $facebook_url; 
}

function get_author_instagram() {
	$author_id = get_the_author_meta( 'ID' );
	$instagram_url = get_field('social_instagram', 'user_' . $author_id);
	return $instagram_url; 
}

function get_author_linkedin() {
	$author_id = get_the_author_meta( 'ID' );
	$linkedin_url = get_field('social_linkedin', 'user_' . $author_id);
	return $linkedin_url; 
}

function get_author_youtube() {
	$author_id = get_the_author_meta( 'ID' );
	$youtube_url = get_field('social_youtube', 'user_' . $author_id);
	return $youtube_url; 
}