pos_sale_report/product_view.xml

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

<openerp>
<data>

<!-- Add entry in the "More" drop down list in form view -->
<act_window id="product_product_pos_sale_report_action"
    key2="client_action_multi"
    name="Sales Statistics"
    res_model="pos.sale.report"
    src_model="product.product"
    view_mode="graph"
    domain="[('product_id', 'in', active_ids)]"
    context="{'search_default_product_groupby': 1}"
    />

<act_window id="product_template_pos_sale_report_action"
    key2="client_action_multi"
    name="Sales Statistics"
    res_model="pos.sale.report"
    src_model="product.template"
    view_mode="graph"
    domain="[('product_tmpl_id', 'in', active_ids)]"
    context="{'search_default_product_tmpl_groupby': 1}"
    />


</data>
</openerp>