If you are in the Navigation window, you can hide a 3D object by clicking the right mouse button over it and selecting the command Hide.
From that moment on you will not see anymore that object in the Navigation window. It will still be available, indeed, in Layout window, where you can repeat the same command in order to Show it again.
The hidden objects will still be available in the project Estimate, as this operation is a pure graphic one.
If you want to totally hide the object, it is better to create a Layer, associate the object to that Layer, and hide the Layer itself.
This article is valid for DomuS3D® 2017 and later versions