How Would you solve the following Expression

[#1]

I need to use set analysis f the following

FirstSortedValue

({<$(vTest1)={'<$(vTargetPercent)'}>}Value,Value)

Where

$(vTest1) is an equation not a field that meets the following equation

[#2 · Accepted solution]

=

FirstSortedValue({<Name={'=$(vTest1) < $(vTargetPercent)'}>}Value,-Value

)