interaction design – Nested sidebar behavior

I have a nested sidebar that goes 3 levels deep. I would like the interaction to slide left/right:

enter image description here

So in this example, if you click on “Jobs” in (1), (2) would then slide in. My question is, when (2) slides in, should its first item be active by default?

I tried that interaction, but the problem is, if the user is creating a job (which would mean they’re filling out a form), if they inadvertently click “< Back”, then the entire screen is going to get replaced by the Home page.

An alternative is – if the user clicks on “Jobs”, this sidebar switches to (2), but nothing is defaulted here. “Create Job” will only bring up that page if they explicitly click on it.