Set the "weight" of fields in the selection, without creating a composite "full-text" index?

Question

NoSQL

There is a test collection with the following fields:
- x ;
- y (array - one-dimensional string type).

Task:
Find records by OR condition between these fields, for example with the value "bar".
At the same time, sort the records so that the " x " field is more important if it contains this value, i.e. those entries were higher...