[MarkLogic Dev General] Separate searchable-expressions for different constraints?

[Karl Erisman]

In a call to search:search, is there any way to specify multiple
searchable-expressions, each applying to a certain set of constraints?
 I want to specify that certain constraints must be satisfied beneath
a specific element and that certain other constraints must be
satisfied beneath another specific element.  Using just one
<searchable-expression> requires that ALL constraints be satisfied
within ONE particular element.

If it's not possible, what would be the recommended way to search for
docs using different criteria for separate subtrees?

Thanks,
Karl