Can we manually provide two labels for a single word?
Not at the same time, no. The ner.manual recipe and UI is primarily designed for named entity recognition, where each token can only be part of one entity, and one entity can only have one label. That's also how most model implementations work.
If you have hierarchical labels that you want to assign to spans of texts, you could start by labelling the top-level categories. Then you can stream in the spans again using the choice interface, and for each span of a top-level category, assign the lower-level categories. This also limits the number of options and some potential for human error.