<stx:transform version="1.0" 
  xmlns:stx="http://stx.sourceforge.net/2002/ns"
  strip-space="yes">

  <stx:buffer name="b1"/>

  <stx:template match="/root">
    <stx:copy>
      <stx:result-buffer name="b1">
	<e/>
      </stx:result-buffer>
      <stx:text>:</stx:text>
      <stx:process-buffer name="b1" group="G2"/>
      <stx:process-buffer name="b1" group="G1"/>
    </stx:copy>
  </stx:template>

  <stx:template match="e">
    <stx:copy>boo</stx:copy>
  </stx:template>

  <stx:group name="G1">

    <stx:template match="e">
      <stx:copy>foo</stx:copy>
    </stx:template>

  </stx:group>

  <stx:group name="G2">

    <stx:template match="e">
      <stx:copy>hoo</stx:copy>
    </stx:template>

  </stx:group>

</stx:transform>