I used this xml code to add a button inside the 'Action',But i need to restrict the button to some user groups,
<record id="specialist_no_show_action" model="ir.actions.server">
<field name="name">No Show </field>
<field name="type">ir.actions.server</field>
<field name="binding_model_id" ref="second_opinion.model_consultation"/>
<field name="model_id" ref="second_opinion.model_consultation"/>
<field name="state">code</field>
<field name="code">
action = model.update_no_show()
</field>
</record>