Views can't create secondary local tasks

I have a views page which i am trying to add as a secondary task to the Admin Content page. I am pretty sure you can't do this with the Views UI only. But even using code I can't seem to find the solution anywhere. I posted this: https://drupal.stackexchange.com/questions/314773/custom-links-task-for-... but still no answer.

This seems like a duplicate of 🐛 Views does not create parent local task for a default local task Needs work anyone disagree?

I believe this one is for secondary level tasks. The one you linked is about a bug where the parent task isn't created automatically when it should.

I don't see any mention of secondary level tasks in there.

I'd keep this open unless that's the problem causing this issue, which it may be.