Aaf: limiting search scope to one or more specific fields

when searching for n-terms like

“term1 term2 term3”

in an index with like 10+ indexed fields.
whats the best way to limit the scope to a subset of all fields?

do i have to generate a query like this:

“field1:term1 field2:term1 field1:term2 field2:term2 field1:term3
field2:term3”

or is there some builtin functionality?

cheers,
Ralf