Hi everyone i'm triying to add a button in a one2many view but i can't show it
my file.xml
<group>
<field name="cost_ids" nolabel="1" colspan="4" >
<tree version="7.0" editable="bottom">
<field name="mat" string="Matiere" />
<field name="teacher_ids" string="Professeurs" domain="[('job_id.name','=','prof')]"/>
<field name="coef_mat" string="Coefficient" />
<field name="charg_hor" string="Charge Horaires" />
<button name="return_action_to_open" type="object" context="{'xml_id':'action_school_unit_form'}" string="unites deval" help="Afficher le bulletin de letudiant" />
</tree>
</field>
</group>