Note: using Firefox on PC, I don't know about mobile experience
Currently, typing a letter in the Add Tab to Group sub-menu may have 2 effects:
A. First letter focus (any letter but G)
The first tab group with the typed letter is focused. When typing the same letter again, the next tag group with the typed letter is focused. When typing a different letter, the first tab group with the typed letter is focused (you cannot type a sequence of letters to search by word, for instance, typing "F-I" will focus a tab group starting with "F" then one starting with "I" and not a tab group whose name starts with "Fi").
If no tab group matches the criterion, nothing happens (on Windows, an error sound is played)
B. New tab group creation (G)
Because the first item `New Group` is bound to G, typing G will start creating a new group, showing a text box appears. From here you can type the name of some new tab group to create.
This means it's impossible to search for a tab group whose name starts with G, and it's impossible to search tab group by name.
My suggestion is to enable full word search, similar to the currently existing tab/tab group/history/favorite search that appears when you type in the URL bar: 1. In the Add Tab to Group sub-menu, you type a sequence of characters => this shows a mini-search box with the characters you typed 2. Below, the matching tab groups appear, with the most relevant ones at the top. As in the URL bar, the matching parts of the words will appear in bold.
3. Optional: You may have a bonus item "Create new tab group with that name". To avoid bothering users who are satisfied with the first match and want to select it with just enter, put the new tab group item at the bottom: if there are few matches, it will be easy to access with a few down key presses, or one up key press to cycle items; if there are zero matches, it will be the only focusable item and thus automatically selected, so user just needs to press Enter to create New group with that name.
Related: Add Tab to Group sub-menu: add sort modes (Recent, Alphabetical, Current order)
since the better the sorting, the less we need word search
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