Receiving error when Previewing Quote Document...created custom formula from Quote Line to grab the "Configured SKU" from the Product Option to group/subtotal the Quote Template: "SBQQ__ProductOption__r.SBQQ__ConfiguredSKU__r.Name"
Formula works fine, it returns the name on the Quote Line, but I added the API name of the new field to the Sub Group Field in the Print Options on the Quote Template and selected the new field and then started getting the error.
Based on the screen shots you provided you have your sub-group field set to SBQQ__Bundle__c, which is a checkbox field. The group and subgroup names need to be text fields. You need to add the API name of the field you created to the picklist values on the SBQQ__SubGroupField__c field. Then select your field in the Sub Group picklist on your quote template.