Add optional FILTER to Query

[aorzelskiGH]

What is missing?

Actually only complete submodels can be queried by /query/submodels.
Several use cases in Factory-X need to retrieve just a few submodel-elements from a large submodel.

How should it be fixed?

FILTER shall be added to Query as optional condition like it is already defined in AccessPermissionRule with mandatory FORMULA and optional FILTER.
The funcionality must already be implemented by a server for the Access Rules, so that just a small change in the frontend parser is needed.

AASPE Server has implemented a POC already.

• I have signed the required Developer Certificate of Origin (DCO) already.

[aorzelskiGH]

The updated Query with FILTER will be:

"Query": {
  "type": "object",
  "properties": {
    "$select": {
      "type": "string",
      "pattern": "^id$"
    },
    "$condition": {
      "$ref": "#/definitions/logicalExpression"
    }
    "FILTER": {
      "$ref": "#/definitions/logicalExpression"
    },
  },
  "required": [
    "$condition"
  ],
  "additionalProperties": false
},

[sebbader-sap]

As discussed in the task force meeting from 04.12.2025: The relevance for this requirement is accepted in principle. Before proceeding however, a dedicated driver for the next query language extensions is needed (same as for #516).

[aorzelskiGH]

See: https://github.com/admin-shell-io/aas-specs-api/tree/aorzelski/issue517

[sebbader-sap]

Please also add an explanation of the desired behavior for FILTERs in https://github.com/admin-shell-io/aas-specs-api/blob/main/documentation/IDTA-01002-3/modules/ROOT/pages/query-language.adoc

[aorzelskiGH]

Will be continued by @Martin187187

[Martin187187]

I created a fork and updated the following to support filters. I am ready to discuss these changes:

• Updated the BNF to support fragment FieldIdentifiers (required for filters) and added $filters
• Added a query filter section with explanation and motivation
• Added two examples using JSON and BNF

[Martin187187]

This issue has to be rereviewed #532 and can be set to "ready for approval" if no more changes are requested