(I should have made clear that this topic addresses Revo.) I’ve found one answer, so if anyone else needs to know, here it is. May be others of course. You filter the results in the chunk, rather than adding conditions to the getResources call. Here’s how.
1) Make your getResources send its findings to a chunk. I’ve called mine ifList:
[[ !getResources? &parents=`8`
&tpl=`ifList`
&includeTVs=`1`
]]
2) Do the filtering in the chunk, using the If snippet:
[[!If?
&subject=`[[+tv.age]]`
&operator=`GT`
&operand=`3`
&then=`yes [[+tv.age]]`
&else=`no [[+tv.age]]`
]]
You will have to download and install the If snippet. It comes with rather thin documentation, so you will have to guess what operators are available