library/library_member/views/library_menu.xml

<odoo>
    <act_window id="action_library_member"
                name="Library Members"
                res_model="library.member"
                view_mode="tree,form"/>
    <menuitem id="menu_library_member"
              action="action_library_member"
              parent="library_app.menu_library"/>
</odoo>