Let's use the simple program below.

Line 15 will be executed 1000 times. And we are only interested with a given iteration, for example we want to ONLY stop at line 15 with condition <data> = 22.

Approach1 - Source code breakpoint in ABAP debugger

Create a new breakpoint in debugger dynamically:

Maintain your condition as below:

And then you should see this new conditional break point set in line 15:

Then F8 to continue, the break point is triggered only once when <data> = 22.

Approach2 - Watchpoint

You should see your created watch point here:

Execute program, watch point is triggered:

Approach3 - ABAP debugger script

Create a new debugger script:

Click "Script Wizard"->"Variable Value(for Simple Variable)":

The wizard will generate code automatically for you ( marked with red ). You can finish the left code to achieve conditional break( marked with blank ). Save your script with a name.

Now launch your program, load the saved Script:

Then click Start Script:

Break point is triggered only once: