I want to ask

q1 is a list radio
a_1
a_2
a_3

q2 is a list radio
a_11
a_22
a_33
a_44
a_55
a_66

if q1 select a_1,q2 display a_11,a_22 option
if q1 select a_2,q2 display a_33,a_44 option
if q1 select a_3,q2 display a_55,a_66 option

How to achieve this way?

Same page or different page ?

See demonstration.sondages.pro/index.php/676785 and adapt for single choice question.
Different page is most easy.

I read the questionnaire. It should be controlled by additional multiple-choice questions. Can I not use additional questions? If single-choice question q1 has 50 options, and single-choice question q2 has 200 options, setting a multiple-choice question will increase 200 fields, and a combination of 5 such questions will soon reach the upper limit of table fields. Is there a better way? Do not pass the additional logic questions?

Then : you need to construct your own system …
(or wait for another helper)

There are plans to add Condition to the answer later?