Syntax for accessing deep roster's variable

Hi, if I have nested roster with depth of 3, i.e., Ro_depth1–>>Ro_depth2–>>Ro_depth3–>>my_question, can I access the inner variable using following syntax: Ro_depth1[idx].Ro_depth2[idx].Ro_depth3[idx].my_question? Thank you in advance.

what is idx?

@sergiy I mean the index,e.g. 0 or 1, …

Addressing like this is possible with the understanding that idx is a row code, NOT a row index.