Hi,

You can try refer the following blog.

https://www.cybrosys.com/blog/how-to-add-smart-buttons-in-odoo-15

Hope it helps

Hi @Ra_one_1_11
here are the XML and python code for your help,

XML: Inherit the corresponding view and add this following code
<xpath expr="//div[hasclass('oe_button_box')]" position="inside">
      <button name="action_view_so" type="object" class="oe_stat_button" icon="fa-shopping-bag">
              <div class="o_stat_info o_field_widget">
                     <span class="o_stat_text">Salespan>
                     <span class="o_stat_text">Ordersspan>
              div>
       button>xpath>

PYTHON:
def action_view_so(self):
       self.ensure_one()
       result =  {'name': _('Sale Orders'),
                      'type': 'ir.actions.act_window',
                      'res_model': 'sale.order',
                      'view_mode': 'kanban,tree,form',
                      'domain': [('partner_id', '=', your_partner_id)],
                     }
        return result