Filter on multiple fields

Currently you can only filter items by looking at one of their fields. I would like the ability to filter on multiple fields to determine what items to update.

For example, if I had a field named "Date" and another field named "Estimate", I would like to be able to say:
````
if field "Date" < 2022-01-01
AND
field "Estimate" >= 5
THEN
update fields
````

Would love to be able to support AND/OR for this too

Start by locating the existing single-field filter entry point and trace how filter conditions select items for updates. Define how multiple fields combine, including the requested AND/OR behavior, and consider the Date and Estimate examples as acceptance cases; done means items are updated only when the combined conditions match.

Written by the indexing model from the issue text.