Hi Dimitri, When you have a question or example please post the 3DM file containing the actual geometry instead of only a screenshot. That helps because then I can make sure I'm using your same objects to test with and to answer your question.

re:
> Below I am putting a simple explanatory image. What we do in such a case when we do want to select
> all the similar faces -as the selected one- on such an object (other than selecting them one by one)?

You can use window selection as I described above, you do not have to select them one by one. Start by selecting one face to make the window selection target faces.

In this case I'd switch to split view and use left-to-right "only target fully contained" window selection like this:



- Michael