As a best practise, we should be grouping the related/targeted steps into a stage which on a whole serves a specific purpose.
I understand that you are looking to navigate to Step2 or Step7 which are in different stages from Step 4 process flow.
You can use Change stage when required, but as both the step2 & 7 are not the first steps on the target stage.
1. You can set a Start when rule(which is true by default) for the earlier steps which comes before the target step on a particular stage
2. Enable "Run on Re-entry" on both the steps 2 & 7.
3. To navigate to Step2 or step7 from the step4 process flow, have a utility shape(activity) containing 2 steps. 1st step to make the when rule to false, 2nd step to call pxChangeStage activity.. in order to skip the before steps in a particular stage so as to reach the targeted step.
This is just a thought, there might be better ways of achieving this.