If you want to apply conditional validation on 'Second Country' or 'Third Country', then you need to add 'Continent' input as 'Asia'
{{countryForm.controls?.continent?.errors?.latLong.message}}
If you want to apply conditional validation on 'Third Country' then you need to add 'Continent' input as 'Asia'.
Conditional Expression with type 'string'
{{countryForm.controls?.thirdCountry?.errors?.latLong.message}}