Currently in AST we are unable to add a module from a CSS selector.
Allowing us to add a module from a previously created CSS selector (from the Create a New Element Filter screen) will allow us to capture parts of pages (e.g headers/footers) and create new modules out of them. The functionality already exists to ignore nodes created in the Ignore Elements section of the Add Module: Capture Node, screen so hopefully this functionality can be recycled to create new modules from these same CSS nodes. Furthermore, it would be fantastic if on the Add Module: Capture Node screen, we could have the ability to add a module from a new CSS selector we find on the page. This way we don't have to rely on previously created nodes and can capture a new module from a new CSS selector right on this screen without having to first create a node. This could use a CSS Selector field just like we have on the Create New Element Filter screen.
It will take more time for testers to capture parts of pages and adding this fix will save testing time. In my experience capturing a module from with the Node Selector button does not always work as I tend to experience glitches with the green border not capturing the correct part of the page. This can be very time consuming and often takes a couple of tries to get right. Using the DOM Selector button is more effective but depending on the length of the DOM, I often find this solution time consuming as well. I am a big fan of the CSS Selector field as this allows us to quickly capture sections of pages and even has a test feature that allows us to confirm that we have the correct section of the page selected.