frustrated over simple search for tags within groups?

I have been using the holidays to try to come to grips with DevonThinkPersonal (looking to upgrade if I can get this working for me).
I can see the potential power that everyone refers to but I am having trouble doing something that seems like it should be very simple! I hope I am simply missing something and one of you helpful experienced people can set me right.

I have set my database up with GROUPS for my main topics, and TAGS for some useful cross-classifying terms.

I can see how clicking on each tag or group name narrows down to just the relevant items. But what I cant see is how to get an intersection of TOPIC3 and TAG6. If I click on both I get anything with EITHER of them, whereas what I want is anything with BOTH of them.

Going to SEARCH doesnt help as I dont see how to search on tags! Plus I want to be able to use this kind of cross classification quickly and easily and search seems powerful but not simple. (The main reason I want to use this so much is I have a tag IMPT that allows me to flag items as important as I input them - there seems no way to do LABEL or FLAG without going into the database; if I am wrong in this please tell me that too!).

Impression so far - a lot of frustration over simple things before I even get to the complexities! One other example - the show/hide tag bar - took me AGES to find the helpful person here who pointed out the tagbar is added at the bottom of the window, not in the obvious spot!

But I hope and trust the learning curve will be worth it - there certainly seem to be lots of fans so maybe I will become one too.

Thanks a million to anyone who can help with this - and Happy New Year

If you go to the Tags view (command-6), selecting multiple tags will give you the intersection of the selected tags.

Thanks a million!
That does seem to achieve what I want - at least if I have ‘groups as tags’ turned on (right?). I was trying to avoid that in order to keep my tag bar uncluttered but if it is necessary for crosscutting I will leave it on.
PS Am I right in thinking there is no way to flag or label an item as you import it?

The Tags view works with regular (blue) tags as well as (gray) group tags, so no-you do not need to have groups as tags turned on.

Are you wanting to auto-flag/label all imported documents, or only flag/label on some criteria? It might be possible to script what you are wanting, depending on the specifics of your desired workflow. However, if it were possible it would require DEVONthink Pro or Pro Office as Personal does not have Applescript support.

Thanks again!
What I want is to select a combination of groups and tags, so I think I need both of them to appear in the tags view - as far as I can work out, it is not possible highlight a group in the left hand panel and a tag in the tags pane.
PS I just want to be able to flag things manually as they go in so I can focus on the important things first when I go in to tidy up. I am happy enough to do this with an IMPT tag now that you have shown me how to do the intersection thing. It just seems like something that would be useful to have as an option on the panel that allows you to set groups and tags as you import.

Now that I’ve re-read your original post, I can see that you want more than just the intersection of tags.

You can get what you want with a search or a smart group, as long as all the documents are in one group and all of its sub-groups. Example with the search function:

Example with a smart group:

Not possible to manually do this on a file-by-file basis, other than to use a temporary tag as you are doing now. It should be easy enough to write a script to then check for the IMPT tag and then flag/label based on that, but I expect that doing this would be more complicated than it is worth.

Fantastic - thanks so much Greg.
I had actually looked in the advanced search but for some reason had missed the ‘tag’ selector, and only seen flag etc. Duh.
Your explanation lets me get ahead with a lot less frustration.
Best wishes and happy new year.