SQL Server 2017

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DECLARE @xml XML = '<ENVELOPE>
    <DSPACCNAME>
        <DSPDISPNAME>Opening Stock</DSPDISPNAME>
    </DSPACCNAME>
    <PLAMT>
        <PLSUBAMT/>
        <BSMAINAMT>-44912711.35</BSMAINAMT>
    </PLAMT>
    <BSNAME>
        <DSPACCNAME>
            <DSPDISPNAME>Stock-in-Hand-Accesories(KPM)</DSPDISPNAME>
        </DSPACCNAME>
    </BSNAME>
    <BSAMT>
        <BSSUBAMT>-15750.01</BSSUBAMT>
        <BSMAINAMT/>
    </BSAMT>
    <BSNAME>
        <DSPACCNAME>
            <DSPDISPNAME>Stock-in-Hand-Accesories(KVM)</DSPDISPNAME>
        </DSPACCNAME>
    </BSNAME>
    <BSAMT>
        <BSSUBAMT>-16750.01</BSSUBAMT>
        <BSMAINAMT/>
    </BSAMT>
    <DSPACCNAME>
        <DSPDISPNAME>Closing Stock</DSPDISPNAME>
    </DSPACCNAME>
    <BSNAME>
        <DSPACCNAME>
            <DSPDISPNAME>Stock-in-Hand-Accesories(KPM)</DSPDISPNAME>
        </DSPACCNAME>
    </BSNAME>
    <BSAMT>
        <BSSUBAMT>-54750.01</BSSUBAMT>
        <BSMAINAMT/>
    </BSAMT>
    <BSNAME>
        <DSPACCNAME>
            <DSPDISPNAME>Stock-in-Hand-Accesories(KRM)</DSPDISPNAME>
        </DSPACCNAME>
    </BSNAME>
    <BSAMT>
        <BSSUBAMT>-74750.01</BSSUBAMT>
        <BSMAINAMT/>
    </BSAMT>
</ENVELOPE>';
SELECT refnode.value('(./DSPACCNAME/DSPDISPNAME)[1]', 'VARCHAR(100)') AS [BSNAME]
     , refnode.value('let $c := . return (../BSAMT[. >> $c]/BSSUBAMT)[1]', 'DECIMAL(18,2)') AS [BSAMT]
     , refnode.value('let $c := . return (../DSPACCNAME[. << $c]/DSPDISPNAME)[last()]', 'VARCHAR(100)') AS [DSPACCNAME]
FROM @xml.nodes('//ENVELOPE/BSNAME') x(refnode)

BSNAME	BSAMT	DSPACCNAME
Stock-in-Hand-Accesories(KPM)	-15750.01	Opening Stock
Stock-in-Hand-Accesories(KVM)	-16750.01	Opening Stock
Stock-in-Hand-Accesories(KPM)	-54750.01	Closing Stock
Stock-in-Hand-Accesories(KRM)	-74750.01	Closing Stock