Put block inside a container as column for example Source: http://magento.stackexchange.com/questions/110747/using-layout-update-xml-to-add-a-block-to-the-sidebar
<referenceContainer name="sidebar.additional">
<block class="Magento\Cms\Block\Block" name="test">
<arguments>
<argument name="block_id" xsi:type="string">test</argument>
</arguments>
</block>
</referenceContainer>
For example this chunck of code put the block catalog.product.related inside the sidebar in product view. El container se define en \\192.168.50.197\Anonymous\c4m2\src\vendor\magento\module-theme\view\frontend\page_layout\2columns-left.xml
<referenceContainer name="div.sidebar.additional">
<block class="Magento\Catalog\Block\Product\ProductList\Related" name="catalog.product.related" template="Magento_Catalog::product/list/items.phtml">
<arguments>
<argument name="type" xsi:type="string">related</argument>
</arguments>
<block class="Magento\Catalog\Block\Product\ProductList\Item\Container" name="related.product.addto" as="addto">
<block class="Magento\Catalog\Block\Product\ProductList\Item\AddTo\Compare"
name="related.product.addto.compare" as="compare"
template="Magento_Catalog::product/list/addto/compare.phtml"/>
</block>
</block>
</referenceContainer>