In Magento 2 its quite simple. (refer to sales/order module) in your ui component you need exportButton under container name="listing_top"

     <exportButton name="export_button">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="selectProvider" xsi:type="string">sales_order_grid.sales_order_grid.sales_order_columns.ids</item>
            </item>
        </argument>
    </exportButton>

updates sales_order_grid by your module keywords and the export is done

Sorry for late reply but I hope it will help someone else In Magento 2 its quite simple. (refer to sales/order module) in your ui component you need exportButton under container name="listing_top"

     <exportButton name="export_button">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="selectProvider" xsi:type="string">sales_order_grid.sales_order_grid.sales_order_columns.ids</item>
            </item>
        </argument>
    </exportButton>

updates sales_order_grid by your module keywords and the export is done

Sorry for late reply but I hope it will help someone else In Magento 2 its quite simple. (refer to sales/order module) in your ui component you need exportButton under container name="listing_top"

     <exportButton name="export_button">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="selectProvider" xsi:type="string">sales_order_grid.sales_order_grid.sales_order_columns.ids</item>
            </item>
        </argument>
    </exportButton>

updates sales_order_grid by your module keywords and the export is done

In Magento 2 its quite simple. (refer to sales/order module) in your ui component you need exportButton under container name="listing_top"

     <exportButton name="export_button">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="selectProvider" xsi:type="string">sales_order_grid.sales_order_grid.sales_order_columns.ids</item>
            </item>
        </argument>
    </exportButton>

updates sales_order_grid by your module keywords and the export is done