Obviously the way you use tab groups in Opus depends upon your personal way of working, so it is difficult to give specific advice. All I can tell you is the way I have chosen to do it.
For instance if you look at my toolbar. The first button is called Working Images. This consists of a Tab Group concerned with the editing of images and their storage. Another called NAS Music contains tabs to list all the various music in the categories I have created on my NAS - and so on.
To create a TAB group you go Preferences/Folder Tabs/Tab Groups... and create them there. There is far more about this in the help files than any advice I can offer here. It is an incredibly feature rich system and arguably the best feature of Opus. I recommend you hack into the help files and create your own tab groups as you require. My button shows you how to attach these tab groups to the toolbar.
If you put some careful thought into the creation of your tab groups you can revolutionize the way you work.
This is what the Working Images Tab Group looks like in Preferences. In Preferences I have named it "Photoshop" but I have attached it to the Working Images button on the toolbar.