You could compute those words and then feed them into context:
documents = tokenizedDocument(["A long winding road"; "The winds from the east"]);
words = documents.Vocabulary;
for word=words(startsWith(words,"wind"))
context(documents,word)
end
To get a single table, you can use arrayfun and vertcat on the resulting tables:
documents = tokenizedDocument(["A long winding road"; "The winds from the east"]);
words = documents.Vocabulary;
words = words(startsWith(words,"wind"));
ctx = arrayfun(@(word) context(documents,word), words,'UniformOutput',false);
vertcat(ctx{:})
