[00:00] Two tier navigation involves having two sets of tabs to navigate around to various areas of your project. Ignition has a built in skeleton project that you can start from when creating a new project in the designer and can customize to fit your needs. You're seeing that skeleton project here. It uses a typical navigation strategy so there's two windows that open on startup; the Dock North Window that contains the tabs that's always open so I can do my navigation, and then the Main Window at the bottom that's going to fill in the rest of the space. Essentially, in the Docked Window, I have two sets of tabs here. I have the first set which is Section One, Section Two, so I can organize various windows into these different groupings. So Section One has Main Window One and Main Window Two. When I click on these tabs, of course, it swaps out the bottom window. But under Section Two it has Main Window Three, click on that, it's going to swap out the bottom. So I can organize all my windows into these different groupings by having that first layer, that first set of tabs. So the designer, when you open that skeleton project, you'll see there's two sets of tabs here in the designer. So the first tier tabs is has no navigation at all. Actually, it's navigation mode is disabled for the tab strip. The second set of tabs, I actually have two, if you look in the project browser I have Section One tabs and Section Two tabs and basically the visible property of each of these are bound to a simple expression looking at the first tier tabs to seeing if it's Section One or Section Two. So my Section Two tabs will only be visible if the first tier tab, the one that's selected, is Section Two. So likewise with Section One it's visible properties bound to the same thing but it's looking for Section One. So these two tabs down here at the bottom, they have Navigation Mode set to Swap To Window. So they know to actually swap out that bottom window automatically. Again, you go into Customizer, you can configure what tabs you want in there. But by having these two sets and marking which tabs you want be visible, you can actually have this two tier navigation. So the user, it looks like they have all their windows organized in different sections.