The spec for this action:
https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf#G11.2111850
An example of a form using this action:
https://www2.illinois.gov/rev/forms/reg/Documents/reg-1-mr.pdf
const groups = [];
      const groupRefs = [];
      
      for (const groupRef of groupsData) {
        if (!isRef(groupRef)) {
          continue;
        }
        groupRefs.push(groupRef);
        const group = this.xref.fetchIfRef(groupRef);
        groups.push({
          id: groupRef.toString(),
          name: isString(group.get("Name"))
            ? stringToPDFString(group.get("Name"))
            : null,
          intent: isString(group.get("Intent"))
            ? stringToPDFString(group.get("Intent"))
            : null,
        });
      }
      config = this._readOptionalContentConfig(defaultConfig, groupRefs);
      config.groups = groups;
    } catch (ex) {
      if (ex instanceof MissingDataException) {
        throw ex;
      }
      warn(`Unable to read optional content config: ${ex}`);
    }
    return shadow(this, "optionalContentConfig", config);
  }
  _readOptionalContentConfig(config, contentGroupRefs) {