Hello everyone!
I have pretty big and complex document with numbers of layers. I want to print different areas of the document depending of my needs and have this area to fit the page (A4 for example).
The point is not to move and scale my drawing to adjust it to printable area, but vice versa, to adjust printable area (A3, A4, ... ) to the part of the document I need to print.

Will very much appreciate help.

Create a rectangle with a desired proportions (with stroke but no fill) and place it over the portion which you`d like to print / go for the Export bitmap, and select Selection as Export area (you`ll need to have this new rectangle selected)

Works very well! Thanks!
Should be somewhere in tutorial.