Add a new tab to WordPress Plugin install Listing

There is the filter: "views_plugin-install" (see here).

You can find it in /wp-admin/includes/class-wp-plugin-install-list-table.php (currently) at line 226:

$views = apply_filters( "views_{$this->screen->id}", $views );

Use it like:

add_filter( 'views_plugin-install', 'my_filter', 10, 1 );

function my_filter( $views ){
    //Do your stuff
    return $views;
}