How do I use the "disable" function ?

a!sideBySideItem(
          item: a!pickerFieldCustom(
            labelPosition: "COLLAPSED",
            placeholder: "Department",
            suggestFunction: rule!INO_departmentSearchSuggestFunction(
              nameList: if(
                rule!INO_isBlank(ri!selectedDepartmentList),
                ri!departmentList.departmentDescription,
                index(
                  remove(
                    ri!departmentList,
                    wherecontains(
                      ri!selectedDepartmentList,
                      ri!departmentList
                    )
                  ),
                  "departmentDescription",
                  null
                )
              ),
              departmentList: if(
                rule!INO_isBlank(ri!selectedDepartmentList),
                ri!departmentList,
                remove(
                  ri!departmentList,
                  wherecontains(
                    ri!selectedDepartmentList,
                    ri!departmentList
                  )
                )
              ),
              filter: _
            ),
            selectedLabels: index(
              ri!selectedDepartmentList,
              "departmentDescription",
              null
            ),
            value: ri!selectedDepartmentList,
            disabled: if(
              ri!byMonthOrWeek = cons!INO_REPORT_BY_SUMMARY,
              true,
              false
            ),
            saveInto: {
              ri!selectedDepartmentList,
              a!save(ri!selectedStaffList, null),
              a!save(ri!selectedSupervisorList, null),
              a!save(ri!selectedManagerList, null),
              a!save(ri!selectedSeniorManagerList, null),
              a!save(ri!selectedJobRoleList, null),
              a!save(ri!selectedStaffListReport, null),
              a!save(ri!selectedRegionList, null),
              a!save(ri!selectedRegionsSupportingList, null)
            }
          ),
          showWhen: and(
            not(
              a!isUserMemberOfGroup(loggedInUser(), cons!INO_GRP_STAFF)
            ),
            or(
              and(
                a!isUserMemberOfGroup(
                  loggedInUser(),
                  cons!INO_GRP_SUPERVISORS
                ),
                local!supervisorHasLD
              ),
              contains(
                {
                  cons!INO_DESIG_ID_SENIOR_DIRECTOR,
                  cons!INO_DESIG_ID_DIRECTOR,
                  cons!INO_DESIG_ID_MANAGER,
                  cons!INO_DESIG_ID_SENIOR_MANAGER
                },
                ri!employee.designationId
              )
            ),
            ri!togglePickers
          )
        ),

I use here "disable", but it is not working. Can you please tell me how is it working now?