XSLT 2.0 node variable select by attribute

In my XSLT 2.0 file I want to acess the NewID of following variable if the currentID is equal to the OldID.

<xsl:variable name="Items">
        <Item OldID="test1" NewID = "TEST01"></Item>
        <Item OldID="test2" NewID = "TEST02"></Item>
</xsl:variable> 

Following code:

 <xsl:template match="xmlitem">
        <xsl:value-of select="$Items/Item/@OldID = @currentID" />
    </xsl:template>

returns true but:

<xsl:value-of select="$Items/Item[@OldID = @currentID]/@NewID"/>

is not working. I'm not sure if this is working like this? Or do I have to loop with a for-each?