Hi Felix, did you figure out what you needed then?

To focus on a particular object you can select it and then push the Reset button once (pushing it twice will target all objects regardless of selection like you mentioned).

That will position the 3D viewport's rotation pivot point at the center of that object's bounding box, which means rotation will happen around that point after that, unless you have set the rotation style to "First person", which is a different style that pivots around the eye point itself instead of around a focus point.

It's also possible to set the rotation pivot to one specific point (like say the corner of a box instead of the center) by using the Zoom Area tool on that same toolbar at the bottom of the viewport. That tool lets you zoom to a particular region and the first point that you pick for the center of the region will also become the rotation pivot.

But for the most part if you want to focus on one particular object then select it and push the Reset button at the bottom of the viewport.

You can also right-click the Reset button to make it apply to all 4 viewports instead of only that single one.

- Michael