Advancements are building as of V1.1.0

These are minecraft vanilla advancements/adchievements. While custom should be supported this is not guaranteed.

Link: https://minecraft.gamepedia.com/Advancements

As per advancement gamepedia guidelines, each advancement has a folder;section;advacement name. These by mc standards are called "internal ID" i.e: minecraft:husbandry/tame_an_animal

We need the entire section, the folder(usually a plugin this case minecraft), the section(aka parent) and the name of the advancement we need.

In simple terms:

"folder;section/advancement"

"minecraft;husbandry/tame_an_animal"

Following the above example the setup is rather easy if you find the advancements you want to use.

Setup(BCRanksFree):

 advancements:
  - minecraft;husbandry/breed_an_animal:&7[&a✔&7] Achievement Unlocked; animal Breeder.:&7[&4✘&7] Breed an animal
  - minecraft;adventure/ol_betsy&7[&a✔&7] Achievement Unlocked; Fired a Crossbow.:&7[&4✘&7] Fire a crossbow!

Setup(AdvancedBCRanks):
- advancements;minecraft:husbandry/breed_an_animal;Achievement unlocked: Animal Breeder;Breed an animal

Please make sure the name is correct as per the gamepedia link, else something might not work right.