If your dictionary has composed characters, you will see the option "Search for composed characters using base characters" in the Webonary dashboard under the "Search" tab. Note: You might see this option even if your dictionary doesn't have composed characters as Webonary doesn't know what a composed characters is, it just checks if there are special characters that it doesn't know.
By default, this option is unchecked, as it makes the search slower (considerably, if your dictionary has many entries).
You might want to check this option if you for instance want your users to search a̧a̧lȩ́ with the base characters aale. Please note, that the character a̧ is made of two characters: a + squiggle.
This is different from a normal à which is simply one character with an accent. Diacritics are handled differently and by default Webonary will find words with diacritics using base characters independent of if this option is checked (the user can change this behavior in the "Advanced Search options").