If an intervention has a target group that is multidimensional (and so are the corresponding target values for the result indicators), appropriate programme-specific result indicators should be set. In this case, the column “common output indicator used as basis for target setting” would indeed remain empty (N/a) and the basis should be specified in the name of the indicator.
For example, in an investment priority related to supporting young people, the common output indicator "below 25 years of age" might not really be relevant as only this age group is involved. Instead, it would be more relevant to assess the educational attainment level of participants at the entry into the ESF operation. In this case, where participants with a wide range of educational attainment can participate and expectations for success are very diverse, it is indeed recommended to breakdown the result indicator by educational attainment to avoid the creaming effect and misleading results.
Note that the target value can be expressed either in absolute terms (number of participants) or as a percentage (proportion out of total target group with the result measured by the result indicator).