Hello Firza.

If I don't understand wrong this is what you want to achieve

You have to enclose each button on its own container, select the container, and drag him to the left. do this with the two containers and they will fit in the same line.

The screen by default has 12 columns of space, in this example, I set both containers to 6 columns, so they both fit.

Hope this helps

@Cássio Fagundes de Souza
thank you for the answer ,but still nothing change when i open in mobile view. 

Hi Firza,

You can make use of the Columns2 widget from OutSystems UI:

Your tree widget should look something like this:

You can define on the columns properties the behavior you intend in each one of the device types. In your case you want the PhoneBehavior set to None:

It will get your two buttons in a single row also on mobile.

Hope it helps.

Regards,
João

@João Marques 
thank very helpful my question