Value Set Query to Get Unique Assignment Details

Hi Team,

Need input on Value set Creation to get unique assignment details out of multiple rows. Currently, I am using the below query which gives me 2 rows, due to same date start but different day projected end. As per the requirement, I need to get min of start date and if the start date are same then the max of projected end date. However, I tried the aggregate function use in Value set but it did not work. Hence I thought of going by sorting mechanism and do a rownum = 1 to achieve the required row in a fast