Using search box to search on two forums at once, is it possible?

Thank you for your reply and valuable suggestion! But unfortunately this is not a desired solution for the developers’ community.

Initially English was chosen as a universal language to talk, but we could not say ‘No’ to native Russians who probably is not familiar to fluent English. Thanks to the second forum, they can fully participate in discussions. As a discussion platform, it must be a separate instance. Native community grows such way, I hope non-English speaking people understand me.

Ok, thank you for the given direction!