Check for repeater fields from outside repeaters?

Next question...

I've tried to check for a repeater field from outside the repeater, like this:

<perch:if id="portrait.portraitOK" value="ok" match="eq">
<perch:repeater id="portrait" label="Portrait" divider-before="Portrait einer beteiligten Person" max="1"  scope-parent="true">
    <perch:content id="portraitOK" type="checkbox" value="ok" required="false" label="OK"/>
</perch:repeater>
</perch:if>

It did not work. Do you spot the error?

PS: The reason behind it is that I should combine Filters in the page function with OR, but then also add another criterium with AND. As perch_collection seems to allow only one 'match', I opted for 'match'=>'or', and am trying to move the "and" part into the template – but not inside the repeater, because I don't want any item returned if the criterium isn't met.