Autocomplete only triggered by a key

It’s similar to adding tags, that if I press # then I will have suggestions. Now I want that if I press cc, then I will have suggestions for category, subcategory, subsubcategory, something like that. I’ve looked at the Various Complements, QuickAdd, and Text Expander, but they all seems to not support this.

You could build a plugin that uses an EditorSuggest.