My LimeSurvey version: LimeSurvey Cloud, Version 6.17.11

In question Multiple Numerical Input Q17 I want to change Code of a last subquestion (Q17_SQ012) to "other" jointly with array filter equal to Q16.
Q16 is a multiple choice question with "Other" option activeted.
So that Q17_SQ012 subquestion would appear to user only if the "Other" subquestion text was filled in by user in Q16

As I understand I can edit codes of subquestions in Edit Subquestions tab, but I do not see this tab in my survey builder.
How I can activet Edit Subquestions tab to work directly with subquestions codes?