(Well, Genesis 8 Male (G8M) anatomical elements will work with any Genesis 8 Male character, and the G8F elements will work with any G8F character.) Again, if a character is sold or appears to be underage, the artist will _NOT_ include textures that apply to the anatomical elements, so read the descriptions carefully. They will work with any model, once you've acquired them. The anatomical elements, however, are _generic_. ( For example some characters that are intended to be 'fairy' or 'elf-like' will have slender bodies and DAZ will out of an abundance of caution NOT include anatomical elements with them.) Some characters are intended to be teenager or earlier, and those models will _not_ include anatomical elements, so make sure you're buying a non-teen-adjacent character.
Be specific about the model you're buying, and look to make sure it includes 'anatomical elements'.
If you're buying Genesis 8 characters from the DAZ3D site, you will need one of the DAZ Original 'Pro' models if you want it to include genitals.