Dear Michal, it is not clear from your question which ATENA environment you are using - ATENA Engineering 2D, Engineering 3D, ATENA Science with GiD, or if you modify the ATENA input file (.inp) by hand, and if you are modelling construction process (with removing elements during the analysis), or if you have a problem with deleting elements/volumes/macroelements in preprocessing (i.e., before starting the analysis).

If you like to hide some macroelement or element group in postprocessing, see the Activity command in ATENA 3D or the Postprocess Domain dialog in AtenaWin.

Hello Michal, I assume you have already read the "Tutorial for Construction Process Modelling in ATENA 2D". If you need to turn off displaying reinforcement bars or cables, you can do so in the Options - Activity dialog. For disabling 2D Macroelements, I think the easiest way is to import the results into ATENA 3D for postprocessing (File - Export - Binary results file to export the results from A2D, then read them into A3D through File - Open other - Results by step). You can set the activity there, and I think you won't even need that - when you read a step where a ME is not active, it should not be displayed at all.