Hi,

Try like below.

In views

<?xml version="1.0" encoding="UTF-8"?>

<odoo>

   <data>

       <record id="inherited_tree_view" model="ir.ui.view">

           <field name="name">tree.inherit</field>

           <field name="model">your.model</field>

           <field name="inherit_id" ref="external_id"/>

           <field name="arch" type="xml">

               <xpath expr="//tree" position="attributes">

                   <attribute name="js_class">button_in_tree</attribute>

               </xpath>

           </field>

       </record>

   </data>

</odoo>

in static/src/xml

<?xml version="1.0" encoding="UTF-8"?>

<templates>

   <t t-extend="ListView.buttons" t-name="module_name_input_v16.buttons">

       <t t-jquery="button.o_list_button_add" t-operation="after">

           <button type="object" class="btn btn-primary import_your_action" style="margin-left:10px;">

              Import

           </button>

       </t>

   </t>

</templates>

in static/src/js

odoo.define('module-name.tree_button', function (require) {
"use strict";
var ListController = require('web.ListController');
var ListView = require('web.ListView');
var viewRegistry = require('web.view_registry');
var TreeButton = ListController.extend({
   buttons_template: 'module_name.buttons',
   events: _.extend({}, ListController.prototype.events, {
       'click .import_your_action': '_OpenWizard',
   }),
   _OpenWizard: function () {
       var self = this;
 
   }
});
var InputListView = ListView.extend({
   config: _.extend({}, ListView.prototype.config, {
       Controller: TreeButton,
   }),
});
viewRegistry.add('button_in_tree', InputListView);
});

Regards