producing three sets of output from one file

I'm trying produce three sets of output from one set of data, each of
which are subsets of the preceding.  That is, I have:
    <article audience="A">stuff here</article>
    <article audience="B">stuff here</article>
    <article audience="C">stuff here</article>
    <article audience="A">stuff here</article>
    <article audience="A">stuff here</article>

For audience A, I want to include only the A articles; for audience B, I
want to include both A&B articles, and for audience C, I want to include
them all. I was preparing to just create three different XSL files and
then use Instant Saxon to transform with each XSL. However, since the
output is formatted identically, I suspect there's a much more elegant
way to do it (perhaps passing some parameter when compiling?), but I'm
not sure what I would do.

If this is explainable to a beginner, I'd appreciate any help.  (Or if
this is beyond a beginner's ability, I'd appreciate someone telling me
that... and I'll do the easy three files as I planned and come back to
this at some point in the future.)

Thanks,
Eric

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