schema.json

{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "definitions": {
        "MyModule.Def": {
            "id": "MyModule.Def",
            "type": "object",
            "properties": {
                "nest": {
                    "$ref": "#/definitions/MyModule.Def"
                },
                "prev": {
                    "$ref": "#/definitions/MyModule.Def"
                },
                "propA": {
                    "$ref": "#/definitions/MyModule.SubModule.HelperA"
                },
                "propB": {
                    "$ref": "#/definitions/MyModule.SubModule.HelperB"
                }
            },
            "required": [
                "nest",
                "prev",
                "propA",
                "propB"
            ],
            "additionalProperties": false
        },
        "MyModule.SubModule.HelperA": {
            "id": "MyModule.SubModule.HelperA",
            "type": "object",
            "properties": {
                "propA": {
                    "type": "number"
                },
                "propB": {
                    "$ref": "#/definitions/MyModule.SubModule.HelperB"
                }
            },
            "required": [
                "propA",
                "propB"
            ],
            "additionalProperties": false
        },
        "MyModule.SubModule.HelperB": {
            "id": "MyModule.SubModule.HelperB",
            "type": "object",
            "properties": {
                "propA": {
                    "$ref": "#/definitions/MyModule.SubModule.HelperA"
                },
                "propB": {
                    "$ref": "#/definitions/MyModule.Def"
                }
            },
            "required": [
                "propA",
                "propB"
            ],
            "additionalProperties": false
        }
    }
}