No, that won't work. All the AND would evaluate and check if they're all valid. If not it would evaluate the OR and check if it's valid. The OR usages are individual. For what you're wanting you'd need to use ELSEIF substitutions like the following.

[cb:if user_id != "0" and cb_stad_nr != "nonregle"]CONTENT_HERE[cb:elseif cb_stad_r ="NULL" and cb_stad_r="regle"]CONTENT_HERE[/cb:elseif][/cb:if]

To avoid duplicating your content as long as this isn't inline you could use a language string for CONTENT_HERE so that either would result in the same language string being output and parsed for whatever content you're wanting to display.

The alternative is to use something like a Code or Query field then put all your conditions in your custom PHP or custom SQL then use an IF substitution against the result of that Code or Query field. It would be interesting to be able to support the conditions you're wanting, but I'm not sure how we would be able to handle that syntax as the REGEXP is already very complicated. Maybe we can implement something that just persists the content. Example as follows maybe something we could implement.

[cb:if PARAMETER="REPLACEMENT"]CONTENT_HERE[cb:elseif PARAMETER="REPLACEMENT"][parent_content][/cb:elseif][/cb:if]

Basically some sort of special substitution of some kind that just outputs the parent conditions content on condition match. Have added a feature ticket as it should be doable.

forge.joomlapolis.com/issues/7980

But to avoid duplicating my content, you speak about to use a language string for CONTENT_HERE

I know how to create a langage string in the plugin language but it does not work in my article (I use CB content bot).

In that case it wouldn't work. It'd depend on the location if that usage would work or not. I've added a feature ticket to see about implementing a special usage though to avoid having to duplicate content if the IF substitution syntax can't be improved to support grouping.