I'm trying to display my products barcode number for each component and nested components in the BomOverview. And to be clear, not the actual downloadable/printable pdf report Bom Overview, the actual web page. I believe there are nested templates that are being called to get where I need the barcodes to go. 

The first would be "mrp.report_bom_structure"

<t t-name="mrp.report_bom_structure">

        <t t-set="data_report_landscape" t-value="True"/>

        <t t-call="web.basic_layout">

            <t t-foreach="docs" t-as="data">

                <div class="page">

                    <t t-call="mrp.report_mrp_bom"/>

                </div>

                <p style="page-break-before:always;"> </p>

            </t>

        </t>

    </t>

That one calls for "mrp.report_mrp_bom"

And in report_mrp_bom it calls one more named "mrp.report_mrp_bom_pdf_line"

<t t-name="mrp.report_mrp_bom">

        <div class="o_mrp_bom_report_page container py-3 py-lg-5 px-0 bg-view">

            <div t-if="data.get('lines')">

                <div class="px-3 mb-5">

                    <h1>BoM Overview</h1>

                    <h3 t-esc="data['name']"/>

                    <hr t-if="data['bom_code']"/>

                    <h6 t-if="data['bom_code']">Reference: <t t-esc="data['bom_code']"/></h6>

                </div>

​ ​...... .... ..... ..

​ </tr>

                        <t t-call="mrp.report_mrp_bom_pdf_line"/>

                    </tbody>

                    <tfoot>

                        <tr t-if="data['show_costs']">

                            <td name="td_mrp_bom_f" class="text-end">

                                <span t-if="data['byproducts']" t-esc="data['name']"/>

                            </td>

                            <td class="text-end"><strong>Unit Cost</strong></td>​

<t t-name="mrp.report_mrp_bom_pdf_line">

        <t t-set="currency" t-value="data['currency']"/>

        <t t-foreach="data['lines']" t-as="l">

            <tr t-if="l['visible'] and (l['type'] != 'operation' or data['show_operations'])">

                <td name="td_mrp_code">

                    <span t-attf-style="margin-left: {{ str(l['level'] * 20) }}px"/>

                    <span t-esc="l['name']"/>

                </td>

I have tried and tried and tried, but I always fail. In my custom model I inherit from mrp.bom and I have used various methods that are found from odoo core code such as _get_bom_data, _get_report_data, _get_pdf_line, etc. so that I can pass the barcode in with the data.

For a quick example
class CustomBomStructure(models.Model):

​ _inherit = "mrp.bom" @api.model 

​def _get_bom_data( 

​ ​self, bom, 

​ ​warehouse, 

​ ​product=False, ​ 

​ ​line_qty=False, 

​ ​bom_line=False, 

​ ​level=0, 

​ ​parent_bom=False, 

​ ​parent_product=False, ​ ​ 

​ ​index=0, 

​ ​product_info=False, 

​ ​ignore_stock=False,

​ ): 

# Call the super method to retain the core logic 

bom_report_line = super(CustomBomStructure, self)._get_bom_data( bom, warehouse, product, line_qty, bom_line, level, parent_bom, parent_product, index, product_info, ignore_stock, )

# Loop through each product line (component) and add the barcode for component in bom_report_line.get("components", []): product = component["product"] barcode = product.product_tmpl_id.barcode if product else '' component["barcode"] = barcode

return bom_report_line