^ yeah I understand - that why I said "not sure whether this is feasible in your use-case"
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Could your "source portlet" perhaps show counts for GREEN status projects , AMBER status projects, RED status projects separately ; enabling the links on each of those separate counts (as well as the 'portfolio') and you then have a way of passing the required "filter" to the "destination portlet".
i.e.
user clicks on the portfolio -> destination shows all projects for the portfolio
user clicks on the GREEN count on the portfolio -> destination shows all GREEN projects for the portfolio
(etc)
(and remove the filters from the destination portlet entirely)
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Still not sure whether this is feasible in your use-case though - its those "additional filters" that would be the problem with what I'm suggesting