Row filter condition, show only useremail()-related data

[Ratatosk]

OR(CONTAINS([Ansvar],USEREMAIL()),CONTAINS([Eposter],USEREMAIL()))

The above is working ok, but I’d like to add another condition described below to the formula, but writing out it’s logic is beyond my skills…:

CONTAINS([Eposter], GroupAddress[GroupID]) if USEREMAIL() is the same as GroupAddress[UserEmail]

(GroupAddress is a table that contains the two columns UserEmail and GroupID generated from Google groups.)

Sorry in advance if my explanation isn’t good enough.