Since each file is searched independently of the other you can't achieve the results in a single step. However, you could create an output transform that provides a list of folders with more than one file.
Save the following text to a file, e.g. folders_multiple_files.xsl
<?xml version="1.0"?>
<!-- Folders with more than one hit transform
Copyright (C) Mythicsoft Ltd 2014. All rights reserved.
-->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:rslt="http://www.mythicsoft.com/FileLocator_16Aug2005" version="1.0">
<xsl:output method="text" indent="yes"/>
<xsl:key name="path-match" match="rslt:file" use="rslt:path" />
<xsl:template match="/">
<xsl:apply-templates select="//rslt:file"/>
</xsl:template>
<xsl:template match="rslt:file">
<xsl:if test="generate-id() = generate-id(key('path-match', rslt:path))">
<xsl:if test="count( key('path-match', rslt:path) ) > 1">
<xsl:value-of select="rslt:path"/>
<xsl:text> files:</xsl:text>
<xsl:value-of select="count( key('path-match', rslt:path) )"/>
<xsl:text> </xsl:text>
</xsl:if>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
Then after a search use that transform to list the folders of interest by exporting the results, e.g.

Which would produce output something like this:
S:\Source Code\Admin\UI files:4
S:\Source Code\Browser\List files:2
S:\Source Code\Docs files:10
etc.