Take the 4th smallest formula:

=SMALL(A$1:A$30,SMALL(IF(RANK(SMALL(SMALL(A$1:A$30,ROW($1:$30)),A$1:A$30,1)=ROW($1:$30), ROW($1:$30),31),4))

Array of formulas to ctrl+shift+enter three-key combination to end the input, the last 4 can be changed to other numbers, changed after the 3 keys to press together to take effect.

Take the fourth largest formula:

=LARGE(B$1:B$30,SMALL(IF(RANK(LARGE(B$1:B$30,ROW($1:$30)),B$1:B$30)=ROW($1:$30),ROW($1:$30),31),4))

With the same operation. the same operation as above.