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Example: Let's say we have two custom fields: PCF - Single Autocomplete (let's name it Continent) and PCF - Multiple Autocomplete (let's name it Countries), the second one is populated depending on the value of the first one.
An easy example is following: we have a "countries" table with two columns: country and continent. Our first field will select the continents and the second one will contain the countries from that continent.
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