Steps to be followed to configure the National ID are -
 1. Select Personal Details option in HRIS Sections dropdown as shown below
2. Activate the National ID feature by selecting the checkbox in the first column against the row
3. A table will be visible in which you can select the National ID for each country
If you have multiple companies activated then each country (which is mapped to
  the company) will be shown here, as and when you add a new company its country
  will be shown here (if it is not already here). If Work Status is being captured
  and there are both Local and Expat employees then an additional row for Expats
  will be visible. A different National ID can be captured for Expats.