function my_shop_nav() {
global $bp;

//add menu item
$nav_item = array(
'name' => __( 'My Shop','buddypress' ),
'slug' => 'my-shop',
'default_subnav_slug' => 'my-shop',
'screen_function' => 'show_my_shop',
'position' => 40,
'item_css_id' => 'my-shop',
);

bp_core_new_nav_item($nav_item);

} //end my_shop_nav

add_action( 'bp_setup_nav', 'my_shop_nav', 1000 );



//add content
function show_my_shop() {
add_action( 'bp_template_title', 'my_shop_title' );
add_action( 'bp_template_content', 'my_shop_content' );
bp_core_load_template( apply_filters( 'bp_core_template_plugin', 'members/single/plugins' ) );
}

function my_shop_title() {
echo 'My Shop';
}

function my_shop_content() {
echo 'My Shop';
}