Ok, I think I did it. For whomever is interested:
I created a column of “lectures not to show” using relation with multiple match
Then I created a column of “users that shouldn’t see this lecture” in the lectures list
Then I created a lookup column with the names of the users above
Then, in the inline-list of the lectures, I filtered for “User” isn’t signed-in user…
If you know of a more elegant solution - happy to hear!
Cheers