Logial OR in activity diagrams?

Sorry, I posted this before but messed it up.
Guess I had not enough coffee. Sorry Guys.

Hi guys,
this is probably a simple question but I am struggeling with it since days.
I need to model a logical “OR” between activities and can’t find the right notation. All I found are branches and forks.

In my understanding forks create parallel running threads that must all run. Hence, I understand the semantics of a fork as a logical “AND”.

In my understanding brachnes are used to model mutually exclusive threads. That is only the thread that meets the guard condition in executed. Hence, I understand the semantics of a brach as a logical “XOR”.

But how do I denote if any number (>1) of the parralel threads can be chosen?

Thank you in advance for your help. I am really stuck here!