architecture: how to design / design a double navigation bar interface using Native JS

A design pattern that I admired is a double navigation bar on the left side. When you click on a button on the left, it has two functions. The first is that it controls the second section of the navigation bar that, when clicked, alternates the new content that can act as a further navigation to show content. The second function performed by the first navigation bar is that it loads a new complete route that is only loaded in a section as an iframe area.

How could you / the best solution to design this when, when you click on a button in the navigation bar that loads a new route, the second navigation bar remains in what is loaded and does not load to the state of a bar default navigation, which would happen whenever a new route was created? loaded.

Then, if I had to click on an option that changes the 2nd navigation bar and then click on a new route, I would only change to the new route and it would not affect the 2nd navigation bar.

Double navigation bar