Search for word and chapter at the same time

The user can search for a word considered either as a word and its branches or as a chapter. This is done by selecting a new option in the Find Window accessible via the contextual menu.

Here is an example where this new search makes a difference:
In the English package H, search for "lead ball head". You will get 22 results for this search, the first symptom is:
[a1 - Staphysagria - Head] - * On shaking the head, there is a sensation in a small spot in the middle of the forehead as if there were something heavy like a ball of lead in the brain which would not loosen.

Now do the same search, but first define the word "head" as "word with its branches or as a chapter".
EH now searches for all symptoms with "lead" and "ball" combined with the word "head" or within a chapter called "head".
You get 25 results, the first symptom is:
[al2 - Lyssinum - Head] - Sensation as if a small leaden ball was rolling about in brain.

The word "head" is not part of the symptom text, which is why it is not found by the first search.
When, in the second search, head is also considered as a chapter, the Lyssinum symptom is found, even though the word head is not in the symptom text.