How to send participants to specific blocks

i have 4 sets of questions within my questionnaire, and i have equally randomised whether participants will see set 1 or 2 first. However, if a participant see set 1, i need them to see set 3. Equally if they see set 2 i need them to then see set 4. set 1 -> set 3 Set 2 -> Set 4 it says i can skip them to certain questions etc. but not to specific blocks.