```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/">
    <query_name>Essenti-Hyperte@11:24:31</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <panel>
        <panel_number>1</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>0</hlevel>
            <item_name>(PrevQuery)Essenti-Diabete@11:31:54</item_name>
            <item_key>masterid:8349</item_key>
            <tooltip>Essenti-Diabete@11:31:54</tooltip>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
    <panel>
        <panel_number>2</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>0</hlevel>
            <item_name>(PrevQuery)Hypertensive di@10:15:34</item_name>
            <item_key>masterid:8149</item_key>
            <tooltip>Hypertensive di@10:15:34</tooltip>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
</ns4:query_definition>

```

I want to find patients with a history of both essential hypertension (Essenti-Hyperte@1:24:31) and diabetes (Essenti-Diabete@1:31:54) using the i2b2 query builder. This query will return patients who have been diagnosed with both conditions at any time in their medical history, with a high level of specificity and accuracy. The query combines two panels, one for each condition, with a total of two items in the query.