You can only select a Facility that has been updated in NHIF system. If there are no Hospitals in Kikuyu or Kinoo in the NHIF Self Care portal then it means they have not been updated in the system or they have not applied.
It is the responsibly of the hospital to apply to be added to NHIF as a healthcare service provider. NHIF does not add a facility that has not applied.
After selecting Kiambu County, have you tried to search the hospital you want?