In general you can do nested animations using a hierarchy if Scene Nodes or Sequence Nodes.

You can also use Scene Nodes if you want a 2D animation (for e.g. lower thirds you've already asked about), in this case you can use orthograpic camera.

By state animation do you mean different animations that can be blended / crossfaded into each other?
If yes, the system do not support it on the native level, but you can do similar things by smart wiring. It's not trivial, however.

Can you describe me what are you planning to do so that I can help with more concrete examples?

You can check the following link

https://docs.vizrt.com/viz-artist-guide/3.3/transition_logic_transition_logic.html

And 

Or something like this

https://www.ventuz.com/support/help/V3_02/HowTo/HowToCreateATurntableStateLogic.html

Finally thank you for your assistance 

I see.
You can achieve similar behaviour. However we do not have a separate transition graph for that.

You can add markers to your sequence (Alt + click on the timeline) and you can name them as well.

Put the sequencer into Playing state.
After that use the Halt At Marker property:

That means that the playing will pause at the given marker. If you change to a higher marker, the playing continues until it reaches that marker.

There's an inconvinience though: if you want a transition to a lower marker (for e.g. from 3 to 2) you have to turn on Backwards.

You can create a control board panel using a Pin Collector to make the switching comfortable, similarly to this:

You'll have a panel like this:

You can find the basic knowledge on how to create control panels here:
https://youtu.be/g1T9F5FojqE?t=324

where i can find orthographic camera module?

also when enabling Backwards the animation keep playing and not halting on selected marker?

It's an option on the regular Camera.
Also I recommend setting Ortho Size to HD.  This way later you can specify the position and size your 2D elements in pixels.

After that you can build you 2D anims similar to this:

The advantage of this approach is that you can use the usual 3D editing tools like moving / rotating the rectangles with arrows, adding the animation keys with the capture method (like shown in the Animation tutorial video   https://youtu.be/mF1W917vQXA?t=1772 )  etc.

The sequencer should halt at markers when it's in Bakcwards.

thank you for the screenshots it helping me a lot in understanding the ideas and feature about aximmetry.

but i have been trying to do as you suggest to made a simple 2D animations but the aximmetry show only black screen in preview window as shown in the following screenshot.

how to solve this problem?

Sorry, I forgot that you must pull back the Camera in Z otherwise the image plane will behind the rectangles and you won't see anything. For e.g. let the Z -100 so you'll have space for ordering the layers in Z.

Also the rectangles with their default size will be too small, set a proper size like

Further suggestions:

- If Text Image has transparent background turn on Transparency in the shader, otherwise the text edges will be jagged.

- Set Text Image Size identical to the Rectangle size to get an 1:1 proportion and to avoid stretched text.
Auto Image Size must be OFF !

- Currently the origin is center of the screen. If this bothers you, move the camera a half screen left and down:

(This will move the origin to the bottom left corner.  It's reasonable since the pivot of the rectangles is also in bottom left.  Of course, you can make the whole system top left based, but it also needs a flipped handling of the rectangles.)

Please download and install these packages  (simply double-click them):

https://mab.to/yPT3SVKUT

One adds general lower-third elements to [Common_Studio] to make building easier.
The other adds a complex example similar to your picture into [Studio]:Lower Thirds.

It is based on the orthographic camera approach, not the Placer Precise.

The weather line has not been implemented yet, since it would be more complex. We'll add it later.