To find single item on-hand quantity for all org

SELECT mmt.inventory_item_id   as item_id
        , y.organization_id     as org_id
        , mmt.subinventory_code as subinv
        , sum(mmt.primary_quantity) qty
    FROM
        apps.mtl_material_transactions mmt,
        apps.mtl_system_items msi,
        (SELECT distinct mmt.organization_id, mmt.inventory_item_id
            FROM  apps.mtl_material_transactions mmt,
                  apps.mtl_system_items msi
            WHERE   mmt.organization_id = msi.organization_id
                AND mmt.inventory_item_id = msi.inventory_item_id
                AND msi.segment1 in ('')
                AND trunc (mmt.transaction_date) <= TRUNC (:p_date)) y
    WHERE  
                  mmt.organization_id = msi.organization_id
        AND mmt.inventory_item_id = msi.inventory_item_id
        AND mmt.inventory_item_id = y.inventory_item_id
        AND mmt.organization_id = y.organization_id
        AND mmt.subinventory_code is not null
        AND trunc (mmt.transaction_date) <= TRUNC (:p_date)
    group by  y.organization_id
            , mmt.subinventory_code
            , mmt.inventory_item_id