I want to specify multiple facet prefixes per field

[Yuhao <nf...@yahoo.com>]

I simulated a hierarchical faceting browsing scheme using facet.prefix.  However, it seems there can only be one facet.prefix per field.  For OR queries, the browsing scheme requires multiple facet prefixes.  For example:

fq=facet1:term1 OR facet1:term2 OR facet1:term3

Something like the above is very powerful.  For the hierarchical browsing, at this point what I want is to show the child terms (one level down) of term1, term2 and term3 (but not term4, term5 or term6).  Now, if I add a facet.prefix, say "f.facet1.facet.prefix=term1", it would give me all the child terms of term1, but I also want the children of child 2 and child 3.

So what I want is to be able to do something like this: "f.facet1.facet.prefix=term1 OR term2 OR term3. 

Is there a way to accomplish what I'm looking for?