Does this help:
Use breakpoints in the debugger - Visual Studio | Microsoft Docs[
^] - it has a section on conditional breakpoints.
I tried it with a BP on the Console line:
for (int i = 0; i < 100; i++)
{
Console.WriteLine(i);
}
I set a BP, then right clicked and selected "Conditions..."
Leaving "Conditional Expression", and "is true", in the expression box I typed "Math.Abs(i) == 5" and closed.
The breakpoint triggered only on the sixth iteration.