xml regular expression string in notepad++.How to find a tag which is not inside a particular parent

I have XML tag in the following format

<saw:column columnID="c83" xsi:type="saw:regularColumn">            
<saw:displayFormat>
<saw:formatSpec visibility="hidden" suppress="default" interaction="default" wrapText="true"/>
</saw:displayFormat>            
<saw:columnHeading>               
<saw:displayFormat>
<saw:formatSpec interaction="default"/>
</saw:displayFormat>
</saw:columnHeading>
 <saw:columnFormula>
<sawx:expr xsi:type="sawx:sqlExpression">max("Supply Fact"."Count")</sawx:expr></saw:columnFormula>
</saw:column>

I have to replace the data inside the tag <saw:displayFormat></saw:displayFormat>

The tag is present both inside the <saw:column> tag and is also a child of <saw:columnHeading>. I don't wanna replace the displayformat tag inside columnHeading but wanna replace display format tag under saw:column

I tried <saw:displayFormat>.*?</saw:displayFormat>. This fetches all the display format tags .

How to omit the ones inside <saw:columnHeading>?