Add sub menu in rtMedia media tab in profile menu

functions.php

<?php
// check if function does not exists
if ( ! function_exists( 'rtmedia_add_extra_sub_nav_for_upload' ) ) {
	function rtmedia_add_extra_sub_nav_for_upload() {

		// IMPORTANT Please change the page_slug
		$page_slug = 'file-upload';

		// check if function does not exists
		if ( function_exists( 'get_page_by_path' ) ) {

			// get the page by slug
			$page_data = get_page_by_path( $page_slug );

			// check if the page exists.
			if ( is_object( $page_data ) ) {

				// check if the page id exists.
				if ( isset( $page_data->ID ) ) {
					global $wp_admin_bar;
					global $rtmedia;
					$page_id = $page_data->ID;
					?>
					<li class="rtmedia-nav-item-<?php echo $page_slug; ?>-profile-1-li">
						<a id="rtmedia-nav-item-<?php echo $page_slug; ?>" href="<?php echo get_permalink( $page_id ); ?>">Upload</a>
					</li>
					<?php
				}
			}
		}
	}
}
add_action( 'add_extra_sub_nav' , 'rtmedia_add_extra_sub_nav_for_upload', 10 );

Please the above snippet in functions.php of child themes.

=================IMPORTANT====================
Please change the $page_slug variable to your page slug