Hi,

Are you looking to add new menu after the MY Dashboard menu ? If yes, you can add a new menu in your custom module or from the user interface and set its parent as "Dashboards" menu and set the necessary action for the menu.

Sample:

<menuitem action="action_model_relation" id="ir_model_relation_menu" parent="base.next_id_9"
          groups="base.group_no_one"/>

See:  How To Inherit And Add Menu To Existing Module In Odoo

Thanks